Definition of "sounder"

sounder¹

/ˈsaʊndə(ɹ)/

adjective
1. comparative form of sound: more sound
  Quotations
  The Northern Division Traffic Manager has said that there is no present intention of terminating the service, but the hopes previously entertained of expanding it cannot be entertained until it is operating on a sounder economic basis.
  1961 April, “Talking of Trains”, in Trains Illustrated, page 199

sounder²

/ˈsaʊndə(ɹ)/

noun
plural sounders
1. Something or someone who makes a sound.
2. An instrument used in telegraphy in place of a register, the communications being read by sound.
3. (medicine, dated, plural only) A stethoscope.

sounder³

/ˈsaʊndə(ɹ)/

noun
plural sounders
1. (nautical) A device for making soundings at sea.
2. (nautical) A person who takes soundings.
3. (fishing) A fishfinder.

sounder⁴

/ˈsaʊndə(ɹ)/

noun
plural sounders
1. A group of wild boar.
  Quotations
  It was not only that there were wild boars in it, whose sounders would at this season be furiously rooting about, nor that one of the surviving wolves might be slinking behind any tree, with pale eyes and slavering chops.
  1958, T[erence] H[anbury] White, chapter II, in The Once and Future King, New York, N.Y.: G. P. Putnam's Sons, book I (The Sword in the Stone)
2. A young boar.