adjective

useful

useful, helpful, practical

This is a very useful tool.

This is a very useful tool.

Your advice was very useful.

Your advice was very useful.

This app is useful for learning new words.

This app is useful for learning new words.

useful + noun describing a helpful item This is a very useful tool.

useful ((for sth./-ing)) helpful for a purpose This app is useful for learning new words.

Synonyms: helpful, practical, beneficial; Antonyms: useless, unhelpful

From 'use' + the suffix '-ful', meaning 'full of'. Something that is 'full of use' is useful.

If something is 'full of use', it is 'useful'. The opposite is 'useless' (lacking use).

This page is designed for learning support. Please use it as a learning reference, not as a formal reference.