OXFORD DICTIONARY
Listen, v.intr.
1 a make an effort to hear something. b attentively hear a person speaking.
2 (foll. by to) a give attention with the ear (listened to my story). b take notice of; respond to advice or a request or to the person expressing it.
3 (also listen out) (often foll. by for) seek to hear or be aware of by waiting alertly.
listen in
1 tap a telephonic communication.
2 use a radio receiving set.
listening-post
1 a a point near an enemy's lines for detecting movements by sound. b a station for intercepting electronic communications.
2 a place for the gathering of information from reports etc.
OE hlysnan f. WG
THESAURUS
Listen
NB, attend, attend to, auscultate, be all ears, bend an ear, bug, cock the ears, eavesdrop, examine by ear, give attention, give audience to, give ear, give ear to, hark, hear, hear out, hearken, hearken to, heed, intercept, lend an ear, listen at, listen in, listen to, mind, obey, pay attention to, sit in on, straitened circumstances, tap, wiretap
ROGET THESAURUS
Listen
Hearing
VB
hear, overhear, hark, harken, list, listen, pay attention, take heed, give an ear, lend an ear, bend an ear, catch, catch a sound, prick up one's ears, give ear, give a hearing, give audience to, hang upon the lips of, be all ears, listen with both ears, become audible, meet the ear, fall upon the ear, catch the ear, reach the ear, be heard, ring in the ear.