Entry 1 sense Webster, 1913 Benzyl · Ben·zyl · IPA /ˈbɛnzɪl/ 01 n. A compound radical, C6H5.CH2, related to toluene and benzoic acid; -- commonly used adjectively. 1. A compound radical, C6H5.CH2, related to toluene and benzoic acid; -- commonly used adjectively.(Chem.)