v. & n.
v.tr. & intr. 1 tr. test the depth or quality of the bottom of (the sea or a river etc.). 2 tr. (often foll. by out) inquire (esp. cautiously or discreetly) into the opinions or feelings of (a person). 3 tr. find the depth of water in (a ship's hold). 4 tr. get records of temperature, humidity, pressure, etc. from (the upper atmosphere). 5 tr. examine (a person's bladder etc.) with a probe. 6 intr. (of a whale or fish) dive to the bottom.
n. a surgeon's probe. sounder n.
[ ME f. OF sonder ult. f. L SUB- + unda wave ]