Jug
mid 16th century: perhaps from Jug, pet form of the given names Joan, Joanna, and Jenny .
wiktionary
From Middle English jugge, iugge, of uncertain origin. Possibly a variant of Middle English jubbe, jobbe, iubbe, geobbe, itself of unknown origin; or perhaps continuing (in altered form) Old English ċēac(“pitcher; jug”). Compare also jug(“a low woman, maidservant”), from Jug, familiar form of Joanna.
Blend of Jack Russell + pug
etymonline
jug (n.)
"deep vessel for carrying liquids, usually with a handle or ear," late 15c., jugge, variant of jubbe (late 14c.), a word of unknown origin. Perhaps it is from jug "a low woman, a maidservant" (mid-16c.), a familiar alteration of Jug, a common personal name such as Joan or Judith.
Use as a musical instrument is attested from 1886 in jug-band (American English) "musical ensemble in which the bass line is carried or augmented by a player blowing on the open lip of a jug. "As a quantity of ale or beer, a jug is usually a pint" [Century Dictionary, 1902].
jug (interj.)
representing the sound of the nightingale, 1530s.