Pairing Group Terms:
Axis Terms: These terms may be used as alternate for the Axis Powers term, or used for pairings of the characters involved:
- JIG: A term made up of the first letters of Japan, Italy, and Germany, also used to denote a threesome pairing or love triangle with the three characters in slash fanfiction and art.
- Roberto: The historical Italian name for the actual Axis Powers, also used by some parts of fandom. It combines the first syllables of Rome, Berlin, and Tokyo.
Anko Family (Denmark, Norway, and Iceland): A term based on some history, at one point in history Iceland was in-fact part of the Danish monarchy until he (Iceland) became independent in 1944. Norway and Iceland are brothers and Denmark is seen as the older brother of the two.
APH (Austria, Prussia, and Hungary): Stems from the first letter of each character, and the fact that it is also a very popular acronym for "Axis Powers: Hetalia" Also known as the Frying Pangle.
Asian Trio (China, Japan, and Korea): Since China, Japan, and Korea are all from Asia, this term is used when they are put together. This term sometimes may be used to describe their relationship as romantic or fraternal.
Awesome Trio (America, Prussia, and Denmark): A term based on how these three characters often praise themselves as "awesome".
Bad Brothers (England, Denmark, and Prussia): Also referred to as the "pitiful brothers", "pitiful trio", "FBN" or the "fail brothers", because of their failure at being older brothers and their tendency to drink a lot of alcohol. "FBN" originated from the Japanese word fubin' meaning "pitiful", with the vowels removed.
Bad Boss Trio (Germany, Russia, and China): A grouping that comes from the fact that Hitler, Stalin, and Mao had killed the most people under their respective rules. A rare and controversial grouping, although somewhat inaccurate considering that Hitler was born in Austria.
Bad Touch Trio (France, Prussia, and Spain): A popular term derived from their appearance in the War of Austrian Succession as allies. They have also alternatively been referred to as the Bad Friends Trio, Best Friends Trio, Bad Business Trio, Badass Trio, Bad Company Trio or the FAG Trio (because of their human names:Francis, Antonio, Gilbert). Although unfortunately, many people in the fandom like to call them "The Rapist (France), the Pervert (Prussia) and the Pedophile (Spain)" , the "Bad Friends Trio" or "Bad Touch Trio" (BFT or BTT) are not a bunch of criminals. Contrary to the popular belief, it must be noted France has never raped anybody. Prussia is shown to be quite awkward when it comes to sexual things (recall the episode where he nursed an injured and buxom Hungary), and he is not a pervert. As for Spain, it was merely indicated that he has a love for children, but this does not mean he wants to have sex with them.
Bad Baby Trio (Canada, Germany, Southern Italy/Romano): A grouping of the Bad Touch Trio's "children," as France was once in control of Canada, Prussia is Germany's older brother, and Spain was once in control of Southern Italy (Romano). It is believed that these three were close friends as children due to the fact that the Bad Touch Trio were allies in the past.
Dread Trio (Lithuania, Latvia, and Estonia): Stems from the fact that these three are often depicted as full of dread and trembling (which the alternative name "Trembling Trio" is derived from as well). In fandoms, sometimes known as the "Baltic Threesome" or the "Dead Trio", in some case called the "Weak Trio."
FRUKUS (France, England, America): A newer term for the threesome of France, England and America; comically enough, it is pronounced exactly as it looks, similar to the word "fracas". Derived from the combination of FRUK, and USUK, it was created by fans who were tired of other fans fighting over who England should be paired with. § Frying Pangle (Austria, Hungary, and Prussia): A term used to describe a love triangle or simple grouping of these three. It is a portmanteau of frying pan and triangle. Frying pan comes from the fact that Hungary always hits Prussia when the latter bothers Austria.
Gender Confused Trio (Hungary, Italy and Poland): A very new term. Italy because he used to wear a dress, Hungary because she thought she was a boy as a child and Poland because he cross-dresses.
German Potato Sandwich (Germany, Austria, and Prussia): Used to refer to a grouping of these three. North Italy is sometimes substituted for Austria.
Girly Man Trio (Poland, Finland, and Italy): The three girliest men in the series. Italy because he used to wear a dress and be mistaken for a girl as Chibitalia, Poland because he talks in a valley girl accent and loves pink, and Finland because he's Sweden's "wife."
Hanatama Family (Sweden, Finland, and Sealand): A nickname for this grouping, though rarely in romantic situations. Usually used to describe the three as a family, and derived from Hanatamago's name.
Honda's Bodyguards (Japan, Greece, and Turkey): Used for these three, due to the fact that both characters of Greece and Turkey are linked with Japan.
House of Habsburg (Austria, Hungary, and Spain): The name is based off the historical House of Habsburg, which until the early 20th century ruled in these countries. The alternative spelling Hapsburg is also used. § House of Savoy (France, North and South Italy, and Spain): Based off the historical House Of Savoy, which included all or parts of these countries.
Invisible Trio (Sealand, Canada, and Seychelles): Considering the fact that the three are often ignored.
Kievan Rus Family (Russia, Belarus, and Ukraine): The fandom's designation for this canonical grouping.
Otaku Trio (Japan, France and America) : Considering the fact that the three are the bigger consumers of Manga in the world : 1st Japan, 2nd France and 3rd America.
Ottoman Family (Hungary, Greece, and Turkey): Stems from the fact that both Greece and Hungary were under the control of Turkey (as the Ottoman Empire) for a period of time in their lives. The grouping can also include Bulgaria.
Tomato Gang/Tomato Trio (Spain, South Italy/Romano, and Belgium): Though it usually refers to these three characters, the Netherlands and Cuba are sometimes included due to also having been under Spanish rule. North Italy is also sometimes substituted for Belgium.
Blond Trio (France, England and America)
Magic Trio (England, Norway and Romania): The three markedly possess supernatural powers compared to the other nations, such as England's ability to see spirits and fairies.
Unnoticed Trio (Canada, Prussia, and Sealand): The name was coined due to the fact that these three characters are mostly either unnoticed or ignored.
PIG (Prussia, Italy, and Germany): Refers to a threesome of the two German brothers and Italy, derived from the first letters of their names: Prussia, Italy, Germany.
Stray Trio (England, Japan, and America): Is a term gave to the group involving England, Japan and America. The Japanese fandom uses the word "Hagure" which mean "Stray" in English. It is used to refer to them being friends or a sexual threesome. It is said that they received the such name due to being historically and canonically alone; but they might have been grouped like this because it is stated that England and Japan are the only friends America has, or rather the only ones who can actually tolerate him. It can be assumed that this might be applied to England too. And though Japan has been shown to have more friends, he enjoy spending time with England and has spend a good amount of time with America as they are shown in various strips together.
Note: This information was taken from somewhere else, and there may be be other trios in existence.