by cupopen November 13, 2009
Get the Niamhmug. Niamh is a fake two face who if they have sisters is mean to one of them most commonly the middle child. She normally cheats on tests to get good grades and makes her sister do her homework. She loves to threaten
Niamh : do my homework
by M6ster122 January 3, 2020
Get the Niamhmug. Literally the coolest person(s) on earth. Very funny and easy going until you mention something that isn't so alpha, then the attack you with their pack of hungry friends, often named Ana. They're very emo, and super duper hip. Niamh's can be located in dark, party-light lit rooms. They seem to always be wearing clown makeup, but when not they have a very bendable human like face. Niamh's are epic.
Me (super alpha), trying to make friends: Are you cool?
You, a beta: yes.
me (alpha): Not as cool as Niamh though
*you just fucking die LMAO*
You, a beta: yes.
me (alpha): Not as cool as Niamh though
*you just fucking die LMAO*
by remuss.bookss January 2, 2022
Get the Niamhmug. 
A socially awkward teenager idiot who can't go to the toilet without being scared of other teenagers.
by ThatOnePersonWhoDoesntKnowShit March 22, 2023
Get the Niamhmug. 
Niamh is a funny person who is friends with another funny person, She is so cool and is beautiful. Niamh is usually very gay
by Catgirllolnotfurry January 27, 2022
Get the Niamhmug.