RhymeZone: undercast definitions

Definitions of undercast:

noun: (meteorology) An unbroken or nearly unbroken cloud layer below the point of observation.
noun: (mining) An air-passage crossing a road in a mine by means of an airtight box or channel beneath it.
verb: To allocate the parts in (a play or film) to insufficiently skilled actors.
verb: To throw under or beneath.

(Definitions from Wiktionary)