gaffe or (rare) gaff /gaf/

A blunder

• unfools
• unfooted
• unforbid
• unforbidden
• unforced
• unforced error
• unforcedly
• unforcible
• unfordable
• unforeboding
• unforeknowable
• unforeknown
• unforeseeable
• unforeseeing
• unforeseen
• unforeskinned
• unforested
• unforetold
• unforewarned
• unforfeited
• unforged
• unforgettable
• unforgettably
• unforgivable
• unforgiven