Entry 2 senses Webster, 1913 lumberjack · lum·ber·jack · IPA /ˈlʌm.bɚ.d͡ʒæk/ 01 n. a person who works at lumbering; a lumberman. 1. a person who works at lumbering; a lumberman. 2. The grey jay.(Zool.) [Canadian] Syn. lumberman, timberman.