SIon> A compresSIonstandard derived from LZ77 it is reportedly used in zip, gzip, PKZIP, and png, among others. Unlike LZW, deflate compresSIon does not use patented compresSIon algorithms. Used as a verb to mean to compress (not decompress!) a file which has been compressed uSIng deflate compresSIon. The oppoSIte, inflate, means to decompress data which has been deflated. Deflate is described in RFC 1951. (1997-06-21)