Definition
Something indispensable cannot be dispensed with — remove it and the whole thing fails. From the Latin dispensare, 'to do without', with the negating in-: the indispensable worker whose absence stops the line, the indispensable vitamin without which the body breaks down. It marks the load-bearing part, the keystone. This is the exact opposite of redundant: where a redundant element can be cut with no effect, an indispensable one is the single piece on which all the rest depends — paramount to the structure.
Examples
- Clean water is indispensable to public health.
- Over the years she made herself indispensable to the company.
- Bees play an indispensable role in pollinating the crops we depend on.
Collocations
absolutely indispensable·an indispensable role·indispensable to·prove indispensable
Synonyms
essential·vital·crucial·necessary·requisite
Antonyms
redundant·dispensable·unnecessary
Word family
indispensability (noun)·indispensably (adverb)
In TOEFL & IELTS
A strong upgrade over 'very important' in IELTS Writing: 'an indispensable role/tool/resource'. TOEFL passages use it for keystone species, essential nutrients, and pivotal historical figures. Mind the preposition — indispensable *to* something or someone. Its precise antonym 'dispensable' (and 'redundant') is worth pairing with it, since reading questions often test the contrast.