laxative

Word family

• lax
  adjectiveC1
• laxity
  nounC1

Synonym discussion

Sense: noun/1

All three words describe substances that stimulate bowel movements, but they differ in strength and register. 'Laxative' is the everyday word for any substance — natural or medicinal — that gently helps relieve constipation. 'Purgative' is stronger and more formal; it implies a thorough emptying of the bowels and is more common in medical writing than in daily conversation. 'Cathartic' is the strongest and most clinical of the three; it describes a powerful agent that causes complete evacuation, and it is rarely used outside of medical or pharmacological contexts. For a mild, over-the-counter remedy, say 'laxative'. For a stronger prescription product, 'purgative' fits better. A doctor discussing a colonoscopy preparation is most likely to say 'cathartic'.

Etymology

The word comes from the Latin 'laxativus', meaning 'loosening', which is formed from the verb 'laxare' ('to loosen or relax'). The root 'laxus' means 'loose, slack, relaxed'. The medical sense of a substance that 'loosens' the bowels appeared in English in the late 14th century, first as an adjective and later as a noun.