Green’s Dictionary of Slang

nunquam n.

[Lat. numquam, never]

(UK Und.) a dawdling messenger.

[UK]Awdeley Fraternitye of Vacabondes in Viles & Furnivall (1907) 16: Nunquam is he that when his Maister sendeth him on his errand he wil not come againe of an hour or two where he might haue done it in halfe an houre or lesse.