Entry 1 sense Webster, 1913 nettlesome · IPA /ˈnɛtəlsəm/ 01 adj. same as irritating, 1. 1. same as irritating, 1. See: irritating Syn. annoying, galling, chafing, irritating, pesky, pestiferous, pestilent, plaguy, plaguey, teasing, vexatious, vexing.