di- (1) Look up di- at Dictionary.com
word-forming element meaning "two, double, twice," from Greek di-, from dis "twice," related to duo (see two).
di- (2) Look up di- at Dictionary.com
word-forming element meaning "apart, asunder," form of dis- before certain voiced consonants.
di- (3) Look up di- at Dictionary.com
word-forming element meaning "through; thoroughly," form of dia- before vowels.