When the whole squad agrees that something is great.
Mike: Did you see that booty?
Peter: That shits famtastic!
by Grian5000 May 2, 2016
Get the Famtastic mug.
When you talk about your fam and how fantastic they are.
Fam #1- I can't wait to hang out.
Fam #2- Whenever we hang out, it's famtastic.
by taddy_paddy February 5, 2016
Get the famtastic mug.