a- (OUTSIDE) [prefix] - outside or in addition toextraterrestrial beings (= imaginary creatures which come from outside the planet Earth)an extramarital affair (= a sexual relationship of a married person with someone other than their husband or wife)extracurricular activities (= activities which are not part of the usual school or college course)
EXTR
Meaning of EXTR in English
Cambridge English vocab. Кембриджский английский словарь. 2012