Entry 1 sense Webster, 1913 Centigram /sĕn'-təg-rămˌ/ · Cen·ti·gram · IPA /ˈsɛntɪˌɡɹæm/ 01 n. The hundredth part of a gram; a mass equal to .15432 of a grain. See 3rd Gram. 1. The hundredth part of a gram; a mass equal to .15432 of a grain. See 3rd Gram. See: Gram