Deadly

How to spell deadly

6 letters · 2 syllables

How to pronounce deadly

Say the part in capitals loudest.

What does deadly mean?

1. adjectiveCapable of causing death, or likely to do so.
2. adverbUsed informally to mean extremely or completely.

Deadly in a sentence

• adjective

  The snake's venom is deadly if no antivenom is given quickly.

• adverb

  The lecture was deadly dull, and half the room nodded off.

• adjective

  Firefighters warned that the smoke was more deadly than the flames.

• adverb

  She was deadly serious about meeting the deadline this time.

Where does deadly come from?

Language of origin: Germanic

This word comes from the Old English dēadlic, which combined dēad, meaning 'dead' or 'lifeless', with the suffix -lic, meaning 'having the form or quality of'. The native Germanic root dēad traces back to the same ancient source that gave us 'die' and 'death', and the -lic ending is the ancestor of the modern -ly we still attach to so many adjectives and adverbs. In its earliest use the word literally meant 'subject to death' or 'mortal', but over the centuries the active sense, 'capable of causing death', took over and became dominant. By the later medieval period English speakers were also using it loosely as an intensifier, so that something could be 'deadly serious' or 'deadly dull' without any real risk of dying. The spelling keeps the whole word 'dead' visible inside it, which is a handy reminder that there is no 'e' before the 'd' and no doubling.

How the word is built

• dead (lifeless, from Old English dēad)
• -ly (adjective/adverb suffix meaning 'having the quality of')