Any day of the week in which you start your weekend partying activities, in preparation for the weekend. Example: Dick: Let's go out to the club tonight and get sloshed! Jane: I can't get drunk on a weekday night, I hafta work tomorrow. Dick: Who cares, it's the preekend.
PREEKEND
Meaning of PREEKEND in English
Slang English vocab. Английский сленговый словарь. 2012