Pinhead
noun, slang ·Very common ·Middle school level
Definitions
- 1 The head of a pin. (Frequently used in size comparisons.)
"The moment the nitre was red hot, the coal, previously reduced to small pieces of the size of a pinhead, was projected in portions of one or two grains at a time…"
- 2 A member of the Provisional IRA. derogatory, slang
- 3 the head of a pin wordnet
- 4 A foolish or stupid person. slang
"I don't want to be a pinhead no more / I just met a nurse that I could go for"
- 5 an ignorant or foolish person wordnet
Show 4 more definitions
- 6 A telemark skier. slang
- 7 A human head that is unusually tapered or small, often due to microcephaly, or a person with that trait. Often promoted in freak shows as "human pinheads". slang
"The microcephalic idiot is an unfortunate with a "pinhead," sometimes exhibited as a "what's-it" in circus side-shows, whose mental age never goes beyond that of an imbecile."
- 8 A newborn cricket used as food for pets. slang
"A newly hatched gecko will need pretty small crickets, but you will not have to go all the way down to pinheads."
- 9 The immature juvenile fruiting body of a mushroom prior to its gills opening.
Example
More examples"The parasitic mite, which is the size of a pinhead, was detected at the port of Newcastle, north of Sydney, more than a week ago and has spread to other hives in the state of New South Wales."
Etymology
From pin + head.
So called because they sold pin-on lilies to commemorate the Easter Rising.
Related phrases
More for "pinhead"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.