look up any word, like fleek:
 
1.
When someone thinks they're really clever because they make half their post or Tweet a hashtag. So they do it all the time.
Real life instances of "Hashtag's Disease":

I was home two hours late for curfew. Oh wait, #WHYDOIHAVEACURFEW

I AM IN BED SO EARLY AND IT FEELS SO NICE! #igothomebeforemyparentsdid #notabigdeal
by Screamin' Squirter September 21, 2011