Entry 1 sense Webster, 1913 Semipellucidity /(sĕm`ĭ*pĕl`lū̇*sĭd"ĭ*ty̆)/ · Sem·i·pel·lu·cid·i·ty · IPA 01 n. The quality or state of being imperfectly transparent. 1. The quality or state of being imperfectly transparent.