English
lackwit
From lack + wit.
Proto-Germanic *lakaz ‘limp’
Proto-Germanic *laką
Proto-West Germanic *lak
Old English *læc ‘deficiency’
Middle English lack
English lack
Proto-Indo-European *weyd- ‘to see’
…
Proto-Germanic *witją ‘knowledge’
Proto-West Germanic *witi ‘knowledge’
Old English witt ‘mind, sanity, sense, understanding’
Middle English wit ‘mind, sanity’
English wit
Today it means
noun A witless person; a fool.
Language periods are conventional ranges, not dates for this word.
Etymograph / lackwit