n.
Function: verb
Etymology: Middle English, from Middle French sonder, from Old French *sonde sounding line, probably from Old English or Middle English sund- (as in Old English sundl ī ne sounding line) from sund sea
Date: 15th century
transitive verb
1 : to measure the depth of : FATHOM
2 : to try to find out the views or intentions of : PROBE ― often used with out
3 : to explore or examine (a body cavity) with a sound
intransitive verb
1 a : to ascertain the depth of water especially with a sounding line b : to look into or investigate the possibility <sent commissioners ⋯ to sound for peace ― Thomas Jefferson>
2 : to dive down suddenly ― used of a fish or whale