Old English hlysnan "to listen," from Proto-Germanic *khlusinon (cf. Dutch luisteren, Old High German hlosen "to listen," German lauschen "to listen"), from PIE root *kleu- "hearing, to hear" (cf. Sanskrit srnoti "hears," srosati "hears, obeys;" Avestan sraothra "ear;" Middle Persian srod "hearing, sound;" Lithuanian klausau "to hear," slove "splendor, honor;" Old Church Slavonic slusati "to hear," slava "fame, glory," slovo "word;" Greek klyo "hear, be called," kleos "report, rumor, fame glory," kleio "make famous;" Latin cluere "to hear oneself called, be spoken of;" Old Irish ro-clui-nethar "hears," clunim "I hear," clu "fame, glory," cluada "ears;" Welsh clywaf "I hear;" Old English hlud "loud," hleoðor "tone, tune;" Old High German hlut "sound;" Gothic hiluþ "listening, attention"). The -t- probably is by influence of Old English hlystan (see list (v.2)). For vowel evolution, see bury. As a noun from 1788 (on the listen "alert").
