sound1
  
  n.
    - vibrations which travel through the air or another medium and are sensed by the ear. 
▸a thing that can be heard.
 ▸the area within which something can be heard.
 - 
(also musical sound)
 sound produced by continuous and regular vibrations, as opposed to noise.
 - music, speech, and sound effects accompanying a film or broadcast. 
▸radio broadcasting as distinct from television.
 - an idea or impression conveyed by words.
 
v.
    - emit or cause to emit sound. 
▸utter.
 - convey a specified impression when heard.
 - 
(sound off)
 express one's opinions loudly or forcefully.
 - test (the lungs or another body cavity) by noting the sound they produce.
 
 
  Derivative
  
    - soundless adj.
  - soundlessly adv.
  - soundlessness n.
 
   
  Etymology
  ME soun, from Anglo-Norman Fr. soun (n.), suner (v.), from L. sonus.
 
  
    
sound2
  
  adj.
    - in good condition. 
▸financially secure.
 ▸Brit. informal excellent.
 - based on reason or judgement. 
▸competent or reliable.
 - (of sleep) deep and unbroken.
 - severe:
 a sound thrashing.
 
adv.
 soundly.
 
  Derivative
  
    - soundly adv.
  - soundness n.
 
   
  Etymology
  ME: from OE gesund, of W. Gmc origin.
 
  
    
sound3
  
  v.
    - ascertain (the depth of water in the sea, a lake, etc.) by means of a line or pole or using sound echoes. 
▸find the depth of water in (a ship's hold).
 - Medicine  examine (the bladder or other internal cavity) with a long surgical probe.
 - 
(sound someone out)
 question someone discreetly or cautiously.
 - (especially of a whale) dive steeply to a great depth.
 
n.
 a long surgical probe, typically with a curved, blunt end.
 
  Derivative
  
  Etymology
  ME: from OFr. sonder, based on L. sub- ‘below’ + unda ‘wave’.
 
  
    
sound4
  
  n.
 a narrow stretch of water forming an inlet or connecting two larger bodies of water.
 
  Etymology
  ME: from ON sund ‘swimming, strait’; rel. to swim.