Meaning & use
lethal
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Meanings
adjectivenot comparable
Able to kill; so dangerous it can cause death.
Grammar: Often before a noun: a lethal dose; or after a linking verb: the poison was lethal.
Patterns
- lethal to someone
- a lethal dose
A lethal dose of the chemical is smaller than a teaspoon.
The snake's venom is lethal to small animals.
Police warned that the road was lethal in icy weather.
adjectivecomparablefigurativeinformal
Extremely harmful or very effective at destroying something, often in a non-literal way.
Grammar: Informal figurative use: a lethal combination.
Patterns
- lethal to something
- a lethal weapon
Her lethal serve ended the match.
The striker's lethal finishing destroyed the defense.
Late payments are lethal to a small business.
Common combinations
- lethal dose
- The vet explained the lethal dose for a cat.
- lethal weapon
- The knife was classed as a lethal weapon.
- lethal injection
- The state ended lethal injection last year.
- lethal force
- Officers may use lethal force only as a last resort.
- lethal combination
- Alcohol and driving are a lethal combination.
Synonyms and how they differ
- deadly
- Deadly is more common and casual, while lethal sounds more technical or clinical.
- fatal
- Fatal describes something that actually causes death or ends in it, whereas lethal says it is capable of killing.
- mortal
- Mortal is literary and often applies to wounds or enemies, not to everyday dangers.
- deadly
- Deadly can also be used of people and looks with force, which lethal only does figuratively.
Opposites
Word family
Commonly confused: lethal or lethargic?
lethal vs lethargic
Lethargic means sluggish and low in energy; lethal means able to kill, and the words share only their start.
Practice
The doctor said that the drug becomes ___ if taken in large amounts.
Choose one answer.
Lethal means able to cause death. Lethargic is a look-alike meaning drowsy.
Make it your own
Write a sentence using “lethal”, then check it and compare it with the examples above.