Entry 2 senses Webster, 1913 Complexity /kəm-plĕk'-sət-ē/ · Com·plex·i·ty · IPA /kəmˈplɛk.sɪ.ti/ 01 n. The state of being complex; intricacy; entanglement. pl. Complexities ((#)) 1. The state of being complex; intricacy; entanglement. “The objects of society are of the greatest possible complexity.” — Burke. 2. That which is complex; intricacy; complication. “Many-corridored complexities Of Arthur's palace.” — Tennyson.