Someone who is acting without common sense, a dumb person. (Also Lepus-temperamentalus, the dreaded pygmy-deer killer-rabitt cross. See http://www.sudftw.com/jackcon.htm) Example: What a jackalope! He's hitting on Matt's girl right in front of Matt. And Matt is huge!
JACKALOPE
Meaning of JACKALOPE in English
Slang English vocab. Английский сленговый словарь. 2012