The Collaborative International Dictionary of English v.0.48:
Sounding \Sound"ing\, n.
1. The act of one who, or that which, sounds (in any of the
senses of the several verbs).
2. (Naut.) [From Sound to fathom.]
(a) measurement by sounding; also, the depth so
(b) Any place or part of the ocean, or other water, where
a sounding line will reach the bottom; -- usually in
(c) The sand, shells, or the like, that are brought up by
the sounding lead when it has touched bottom.
Sounding lead, the plummet at the end of a sounding line.
Sounding line, a line having a plummet at the end, used in
Sounding post (Mus.), a small post in a violin,
violoncello, or similar instrument, set under the bridge
as a support, for propagating the sounds to the body of
the instrument; -- called also sound post.
Sounding rod (Naut.), a rod used to ascertain the depth of
water in a ship's hold.
In soundings, within the eighty-fathom line. --Ham. Nav.