/geek/ , n. Slang.
1. a carnival performer who performs sensationally morbid or disgusting acts, as biting off the head of a live chicken.
2. a peculiar or offensive person, esp. one who is perceived to be overly intellectual.
3. an expert in computers (a term of pride as self-reference, but often considered offensive when used by outsiders.)
[ 1915-20; prob. var. of geck (mainly Scots) fool gek ]