ASL sign for STUPID
Meaning: lacking intelligence or common sense or keenness of mind; dull.
A Hearing Blooper
The trend of #FOREHEADPEACESIGN in the hearing world online around 2017 was actually interpreted as #IAMSTUPID in ASL.
Though, this PEACE/STUPID blunder, err, blooper seems to be short-lived.
Related signs: DUMB, IGNORANT, GULLIBLE, IDIOT, SIMPLE-MINDED, UNINTELLIGENT.