bark (n.1)

"tree skin, hard covering of plants," c. 1300, from a Scandinavian source akin to Old Norse börkr "bark," from Proto-Germanic *barkuz, which probably is related to birch and Low German borke. The native word was rind.

"any small vessel or ship," early 15c., from Middle French barque "boat" (15c.), from Late Latin barca, which is probably cognate with Vulgar Latin *barica (see barge (n.)). More precise sense of "three-masted ship fore-and-aft rigged on the mizzenmast" (17c.) often is spelled barque to distinguish it.

"utter an abrupt, explosive cry" (especially of dogs), Middle English berken (c. 1200), bark (late 15c.), from Old English beorcan "to bark," from Proto-Germanic *berkan (source also of Old Norse berkja "to bark"), of echoic origin. Related: Barked; barking. To bark at the moon "complain uselessly" is from 1650s. To bark up the wrong tree "mistake one's object, attack or pursue something other than what is intended" is U.S. colloquial, first attested 1832, from notion of hounds following the wrong scent.

dog sound, Old English beorc, from bark (v.). Paired and compared with bite (n.) at least since 1660s; the proverb is older: "Timid dogs bark worse than they bite" was in Latin (Canis timidus vehementius latrat quam mordet, Quintius Curtius).

"strip off the bark" (of a tree), 1540s, from bark (n.). Transferred sense "strip or rub off the skin" is from 1850. It also meant "kill a squirrel or other small animal by percussive force by shooting the bullet into the tree immediately below it," thus preserving the specimen intact (the technique is attested by 1828). Related: Barked; barking.