Diagnostic

How to spell diagnostic

10 letters · 4 syllables

How to pronounce diagnostic

Say the part in capitals loudest.

What does diagnostic mean?

1. adjectiveRelating to the identification of a problem, illness or fault through examination of its signs.
2. nounA test, procedure or distinguishing feature used to identify a condition or fault.

Diagnostic in a sentence

• adjective

  The mechanic ran a diagnostic check before quoting for the repair.

• noun

  The software ran a full diagnostic and flagged the failing hard drive.

• adjective

  The hospital invested in new diagnostic equipment for early cancer detection.

• noun

  A raised temperature is a useful diagnostic in the early stages of infection.

Where does diagnostic come from?

Language of origin: Greek

This word traces back to the Greek diagnostikos, meaning 'able to distinguish' or 'good at telling things apart'. It was built on the verb diagignoskein, which combined dia, meaning 'apart' or 'through', with gignoskein, meaning 'to know' or 'to perceive'; together they meant to know something thoroughly by telling it apart from other things. The related noun diagnosis travelled into English through medical Latin in the 1600s, and diagnostic followed as the adjective describing anything that helps identify a condition. The same gignoskein root sits inside familiar relatives such as 'know', 'cognition' and 'prognosis', all bound up with the act of recognising. The silent 'g' before the 'n' is the spelling trap here, and it survives precisely because the original Greek stem was gnos, the very part that carries the meaning 'to know'.

How the word is built

• dia- (apart, through)
• gnos (to know)
• -tic (adjective-forming suffix)