castor
UK[ˈkɑːstə]US[ˈkæstər]
n
A small container with holes in the top, used for sprinkling salt, sugar, etc.
n
A small wheel fixed to the bottom of a piece of furniture so that it can be moved easily.
n
A beaver, or a substance obtained from it.
Etymology
The word 'castor' has a journey that intertwines language and mistaken identity. It entered English from the Latin 'castor', meaning "beaver". The Latin term was a direct borrowing from the Greek 'kastōr' (κάστωρ), which also meant beaver. Interestingly, the Greek word is believed to be a folk-etymological alteration of an earlier, non-Greek term for the animal, possibly influenced by the name of the mythological hero Castor. This classical path gave English the zoological sense. The meanings related to a swiveling wheel and a sprinkler bottle, however, arose later through different semantic shifts. The wheel sense likely derives from a proprietary use of the word, while the container sense may be a separate borrowing from a different Romance language root meaning "to sprinkle".
Analysis
The word 'castor' is a simplex loanword adopted into English from Latin, where it meant "beaver". The Latin term was itself borrowed from Greek 'kastōr'.
Examples
The heavy armchair was fitted with smooth castors for easy movement.
She reached for the castor to add a pinch of sugar to her tea.
Castor oil is a vegetable oil derived from the seeds of the castor bean plant, unrelated to the animal.