Guy is a boy’s name of Celtic, English, French, German, Hebrew, Latin and Teutonic origin. Meaning in Celtic: Sensible. Meaning in English: A name derived from the Hebrew ‘goy’, meaning Gentile. Also a colloquial term used to refer to a man. Meaning in French: Guide. Meaning in German: From the Old German name Wido, meaning wood. Meaning in Hebrew: Valley. Meaning in Latin: Life. Meaning in Teutonic: Warrior. Famous bearer: the British Guy Fawkes. The name has 3 letters.