The Collaborative International Dictionary
Nipperkin \Nip"per*kin\, n. [See 1st Nip.] A small cup. [Obs.]
Wiktionary
n. 1 (context archaic English) A small cup or other vessel, of perhaps 1/8 pint in volume. 2 (context archaic English) A small amount of beer, wine, or other liquid, of perhaps 1/8 pint in volume.
Wikipedia
The nipperkin is a unit of measurement of volume, equal to one-half of a quarter-gill, one-eighth of a gill, or one thirty-second of an English pint. In other estimations, one nip (an abbreviation that originated in 1796) is either one-third of a pint, or any amount less than or equal to half a pint. A nipperkin is also one-eighth of a pint of beer or any other liquor.
Usage examples of "nipperkin".
I have set a nipperkin of toddy by me, just by way of spell, to keep away the meikle horned deil, or any of his subaltern imps who may be on their nightly rounds.
Caryll with an air almost apologetic, and to the landlady with an air scarcely less so, as he asked for a nipperkin of ale to wash the dust of the road from his throat.