castor

Everyday

1. A small wheel fixed under a chair, bed, trolley or piece of furniture so it can be moved easily (also spelled "caster"). tree →
2. In "castor oil": a thick, bad-tasting oil from the seeds of the castor oil plant, once given to children as a medicine. tree →
3. In "castor sugar" (UK, also "caster sugar"): very fine white sugar used in baking. tree →
4. (a name) Castor is a bright star in the Gemini constellation, named after one of the twins in Greek myths. tree →
5. Castor can also be the name of a twin hero from Greek myths, who was a famous horseman. tree →

In the lessons

In everyday life office chairs and hospital beds roll on castors. In history and old stories castor oil was a nasty medicine children dreaded. In baking lessons caster or castor sugar dissolves quickly in cakes and meringues. In astronomy, Castor and Pollux are the twin stars of Gemini.

Examples

• The office chair rolls on five castors. tree →
• One castor broke, so the trolley wobbles. tree →
• In old books, children were given a spoon of castor oil. tree →
• Use castor sugar to make meringues. tree →
• Castor and Pollux are the brightest stars in Gemini. tree →
• Castor oil comes from the seeds of the castor bean plant. tree →
• They were also famous for their physical accomplishments, Castor being the most expert charioteer of his day, and Pollux the first of pugilists. tree →

Note

Spelling: both castor and caster are used for the wheel and the sugar. Safety: the seeds of the castor oil plant are very poisonous to eat, though the oil itself is processed safely. The star Castor has a capital C.