Pinhead refers to someone who is considered stupid or foolish. Synonyms for the word "pinheads" may include terms like simple-minded, dim-witted, clueless, dense, doltish, unintelligent, and brainless. Other synonyms may include terms like imbecile, nincompoop, blockhead, dunderhead, and numskull. These words are used to describe individuals who lack intelligence or common sense. While some may consider such language offensive, they are commonly used in everyday language, often in a playful way to describe someone who has done something silly or foolish. It is important, however, to use discretion when using such words and avoid causing offense.