deadly
dead·ly/ˈdɛdli/adjective, adverb
deadly is spelled D-E-A-D-L-Y: 6 letters and 2 syllables (dead·ly). It appears 14 times per million words in written English, the 5,496th most frequent word form (wordfreq, 2021 data). As an adjective, deadly means “Causing death; lethal” (English Wiktionary, September 2026).
How many letters and syllables are in deadly?
| Letters | 6: D-E-A-D-L-Y |
|---|---|
| Syllables | 2: dead·ly |
| In writing | 14 times per million words; the 5,496th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is deadly?
Deadly appears 14 times per million words in written English, the 5,496th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce deadly?
- US /ˈdɛdli/
Deadly has 2 syllables, split dead·ly in writing.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-deadly.ogg, Wikimedia Commons (author and licence on each file's page).
Forms of deadly
- deadlier comparative
- more deadly comparative
- deadliest superlative
- most deadly superlative
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does deadly mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
obsoleterareSubject to death; mortal.
- 2
Causing death; lethal.
- 3
Aiming or willing to destroy; implacable; desperately hostile.
deadly enemies
- 4
Very accurate (of aiming with a bow, firearm, etc.).
- 5
informalVery boring.
- 6
IrelandinformalExcellent, awesome, cool.
adverb
- 1
obsoleteFatally, mortally.
- 2
In a way which suggests death.
Her face suddenly became deadly white.
- 3
Extremely, incredibly.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Deadly in Spanish, French, German and Portuguese
In the sense lethal:
| Language | Words |
|---|---|
| French | mortel, fatal, létal |
| German | tödlich |
| Portuguese | mortal, fatal, letal, mortífero, fatífero |
| Spanish | exicial |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does deadly come from?
From Middle English dedly, dedlych, dedlich, from Old English dēadlīċ (adjective), from Proto-West Germanic *dauþalīk, from Proto-Germanic *dauþalīkaz (“deadly”, literally “deathly”). By surface analysis, dead + -ly.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).