Entry 2 senses · 2 variants Webster, 1913 Overdose /ōv'-ẽrd-ōsˌ/ · O·ver·dose · IPA /ˈəʊvə(ɹ)ˌdəʊs/ v. t. n. 01 v. t. To dose to excess; to give an overdose, or too many doses, to. 1. To dose to excess; to give an overdose, or too many doses, to. 02 n. Too great a dose; an excessive dose. 1. Too great a dose; an excessive dose.