"tree skin," c. 1300, from a Scandinavian source akin to Old Norse borkr "bark," from Proto-Germanic *barkuz, which probably is related to birch and Low German borke. The native word was rind.
bark (n.2)
"any small ship," early 15c., from Middle French barque (15c.), from Late Latin barca (c. 400 C.E.), probably cognate with Vulgar Latin *barica (see barge). More precise sense of "three-masted ship" (17c.) often is spelled barque to distinguish it.
bark (v.)
in reference to a dog sound, Old English beorcan "to bark," from Proto-Germanic *berkan (cognates: Old Norse berkja "to bark"), of echoic origin. Related: Barked; barking. To bark up the wrong tree is U.S. colloquial, first attested 1832, from notion of hounds following the wrong scent.
bark (n.3)
dog sound, Old English beorc, from bark (v.). Paired and compared with bite (n.) since at least 1660s; the proverb is older: "Timid dogs bark worse than they bite" was in Latin (Canis timidus vehementius latrat quam mordet, Quintius Curtius).