Castling

noun

1. An abortion, or a premature birth.

   "1646: Wherein notwithstanding, we should rather rely upon the urine in a castling’s bladder — Sir Thomas Browne, Pseudodoxia Epidemica, Book II, ch 5"

2. The second or third swarm of bees which leaves a hive in a season.
3. A miniature cast or mould.
4. One that is cast.