Entry 1 sense Webster, 1913 Knotwort /(nŏt"wûrt`)/ · Knot·wort · IPA 01 n. A small, herbaceous, trailing plant, of the genus Illecebrum (Illecebrum verticillatum). 1. A small, herbaceous, trailing plant, of the genus Illecebrum (Illecebrum verticillatum).(Bot.)