Entry 1 sense Webster, 1913 Cellulitis · Cel·lu·li·tis · IPA /ˌsɛl.jəˈlaɪ.tɪs/ 01 n. An inflammantion of the cellular or areolar tissue, esp. of that lying immediately beneath the skin. 1. An inflammantion of the cellular or areolar tissue, esp. of that lying immediately beneath the skin.