I. ˈslag noun
Etymology: Middle Low German slagge
Date: 1552
: the dross or scoria of a metal
II. noun
Etymology: earlier argot slag coward, worthless person
Date: circa 1958
slang chiefly British : a lewd or promiscuous woman
III. transitive verb
( slagged ; slag·ging )
Etymology: probably from slag (II)
Date: 1971
chiefly British : to criticize harshly