Entry 1 sense Webster, 1913 Hyperplasia /hīpˌ-ẽrp-lāzh'-ä/ · Hy·per·pla·si·a · IPA /ˌhaɪ.pɚˈpleɪ.ʒə/ 01 n. An increase in, or excessive growth of, the normal elements of any part. 1. An increase in, or excessive growth of, the normal elements of any part.(Med. & Biol.)