def
6 synonyms and 0 antonyms for def, grouped by meaning and by how common each one is.
Adjective — Slang: excellent or very good.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
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.
Etymology
A 1980s hip-hop slang clipping, most likely from "definitive" or "definitely."
Full origin of def →Frequently asked questions
What does “def” mean?
The word “def” means slang: excellent or very good.
How do you pronounce “def”?
“Def” is pronounced dehf (/dɛf/ in IPA).
How do you use “def” in a sentence?
Here is “def” used in a sentence: “That new track is def, you have to hear it.”
What part of speech is “def”?
“Def” is an adjective.
Where does the word “def” come from?
The word “def” dates back to around 1980. A 1980s hip-hop slang clipping, most likely from "definitive" or "definitely.".
Is “def” a common word?
“Def” is a fairly common word in modern English.
What is the difference between "def" as slang and "def" as an abbreviation?
As slang, "def" is an adjective meaning excellent or very good, as in "that track is def". Separately, "def" is often used online as a short, informal spelling of "definitely", as in "I'm def coming" — two different uses that look the same.
Is "def" formal or informal?
"Def" is informal slang and is best kept to casual speech, texting, and social media. In formal writing you would use a word like "excellent" instead, or spell out "definitely" if that is the meaning.
What words mean the same as "def" when it means excellent?
When "def" means excellent or very good, similar informal words include "dope", "sick", "wicked", "rad", and "awesome". Like "def", these are casual and used mainly in speech and informal writing.