(VERB) To consume alcohol, generally a large amount, at one's own place of residence or that of a friend, as a precursor to going out to a party, bar or club. Also 'prelash'(NOUN). Can be practised alone or in groups. Often performed at the same time as getting changed, putting on make up or straightening hair. Favourite pastime of students. Can involve drinking games such as 'Ring of Fire.' Generally considered to be a cheap, convenient alternative to drinking in bars before clubs open.
'Are we prelashing at Dave's tonight or just going straight to the bar?'