It is accurately defined as a phrase used in an intense situation in which something good or bad has happened and "aw snap" or "snap" are not effective.
by jeff August 7, 2004
Fasnaps is a type of fake Snapchat account. Kind of like a Finsta (Finsta is a fake insta for funny and embarrassing pics aside from a normal Instagram) so a Fasnaps is a fake snapchat account for close friends to see you posting what you normally are like.
by Imakemywords. February 17, 2016