bridegroom (n.) Look up bridegroom at Dictionary.com
Old English brydguma "suitor," from bryd "bride" (see bride) + guma "man," from Proto-Germanic *gumon- (source also of Old Norse gumi, Old High German gomo, from suffixed form of PIE root *dhghem- "earth" (compare homunculus). Ending altered 16c. by folk etymology after groom (n.) "groom, boy, lad" (q.v.).

Common Germanic compound (compare Old Saxon brudigumo, Old Norse bruðgumi, Old High German brutigomo, German Bräutigam), except in Gothic, which used bruþsfaþs, literally "bride's lord."