Entry 2 senses · 2 variants Webster, 1913 wiretap · IPA /wˈaɪərtˌæp/ n. v. t. 01 n. the act or event of tapping a telephone or telegraph line to get information surreptitiously. 1. the act or event of tapping a telephone or telegraph line to get information surreptitiously. 02 v. t. to tap{5} (a telephone or telegraph line) to get information surreptitiously; also, to obtain or record (information) by use of a wiretap. 1. to tap{5} (a telephone or telegraph line) to get information surreptitiously; also, to obtain or record (information) by use of a wiretap.