Entry 1 sense Webster, 1913 Expertness · Ex·pert·ness · IPA 01 n. Skill derived from practice; readiness; as, expertness in seamanship, or in reasoning. 1. Skill derived from practice; readiness; as, expertness in seamanship, or in reasoning. Syn. Facility; readiness; dexterity; adroitness; skill. See Facility.