deadly
16 synonyms and 1 antonym for deadly, grouped by meaning and by how common each one is.
Adj — Capable of causing death.
Synonyms
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
life-threatening
venomous
pestilent
virulent
deathly
pernicious
baneful
lifelessly
insanely
deucedly
devilishly
madly
Synonyms by Meaning
1. adj
Capable of causing death.
“Some wild mushrooms are deadly, so never eat one you cannot identify.”
lethal
fatal
mortal
life-threatening
venomous
murderous
pestilent
virulent
deathly
pernicious
baneful
Opposites
2. adv
Extremely; used to intensify an adjective.
“The film was deadly serious about its message.”
How to use deadly
The word patterns that sound natural to a native speaker.
deadly weapon
deadly virus
deadly accurate
deadly serious
Etymology
From Old English deadlic, built from dead plus -lic (the ancestor of -ly), literally "death-like".
Full origin of deadly →Frequently asked questions
What does “deadly” mean?
The word “deadly” means capable of causing death. In plain terms, able to kill, or (informally) extremely something — usually extremely boring or extremely skilled.
How do you pronounce “deadly”?
“Deadly” is pronounced DEHD-lee (/ˈdɛdli/ in IPA).
How do you use “deadly” in a sentence?
Here is “deadly” used in a sentence: “The snake's venom is deadly if left untreated.”
What part of speech is “deadly”?
Depending on how it is used, “deadly” can be an adjective and an adverb.
Where does the word “deadly” come from?
The word “deadly” comes from Old English. From Old English deadlic, built from dead plus -lic (the ancestor of -ly), literally "death-like".
Is “deadly” a common word?
“Deadly” is a fairly common word in modern English, usually learned at around the B1 level.
How many meanings does “deadly” have?
“Deadly” has 3 distinct senses listed in this dictionary. The most common is: capable of causing death.
What is the difference between "deadly" and "deathly"?
"Deadly" means capable of causing death, as in a deadly poison. "Deathly" means resembling death or suggesting it, as in "deathly pale" or "deathly silence," and does not mean actually able to kill.
What is the difference between "deadly" and "lethal"?
Both mean able to cause death, and they often overlap. "Lethal" tends to sound more technical or clinical, as in "a lethal dose," while "deadly" is more general and can also mean extremely effective, as in "deadly accurate."
What is the difference between "deadly" and "fatal"?
"Deadly" describes something with the potential to cause death, such as a deadly weapon, before any harm has happened. "Fatal" usually describes something that actually did cause death, such as a fatal accident.
