Entry 4 senses · 3 variants Webster, 1913 Drilling · Drill·ing · IPA /ˈdɹɪlɪŋ/ n. n. n. 01 n. The act of piercing with a drill. 1. The act of piercing with a drill. 2. A training by repeated exercises. 02 n. The act of using a drill in sowing seeds. 1. The act of using a drill in sowing seeds. 03 n. A heavy, twilled fabric of linen or cotton. 1. A heavy, twilled fabric of linen or cotton.(Manuf.)