The Collaborative International Dictionary of English v.0.48:

Runlet \Run"let\, n.
   Same as Rundlet. "A stoup of sack, or a runlet of canary."
   --Sir W. Scott.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rundlet \Rund"let\, n. [Dim. of OF. rondele a little tun, fr.
   rond round. See Round, and cf. Roundlet, Runlet.]
   A small barrel of no certain dimensions. It may contain from
   3 to 20 gallons, but it usually holds about 141/2 gallons.
   [Written also runlet.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Runlet \Run"let\, n. [Run + -let.]
   A little run or stream; a streamlet; a brook.
   [1913 Webster]

         To trace out to its marshy source every runlet that has
         cast in its tiny pitcherful with the rest. --Lowell.
   [1913 Webster]