DEF Definition & Meaning - Merriam-Webster
What does the abbreviation DEF stand for? Meaning: defendant; defense. How to use def in a sentence.
Diesel Exhaust Fluid - Shop DEF Fluid - AutoZone
Reduce emissions and keep your diesel vehicle running clean with diesel exhaust fluid (DEF) from AutoZone. We sell the best brands, including AutoZone, Lumax, and Peak Blue DEF fluid.
Dictionary.com | Meanings & Definitions of English Words
3 days ago · The world’s leading online dictionary: English definitions, synonyms, word origins, example sentences, word games, and more. A trusted authority for 25+ years!
def - Wiktionary, the free dictionary
Sep 30, 2025 · def (plural and weak singular deve) Deaf; unable to hear: (figuratively) Inanimate, non-living. Unhearing; unwilling to hear. (Late Middle English) Worthless, empty: (surgery) …
DEF | definition in the Cambridge English Dictionary
DEF meaning: 1. very good: 2. very good: . Learn more.
DEF definition and meaning | Collins English Dictionary
8 meanings: slang very good, esp of hip-hop definition → 1. a formal and concise statement of the meaning of a word, phrase,.... Click for more definitions.
def noun - Definition, pictures, pronunciation and usage notes
Definition of def noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
Find Definitions & Meanings of Words | Britannica Dictionary
19 hours ago · Clear and simple definitions in American English from Britannica's language experts. More usage examples than any other dictionary.
Def - definition of def by The Free Dictionary
def Also found in: Thesaurus, Medical, Legal, Financial, Acronyms, Idioms, Encyclopedia, Wikipedia.
What Does DEF Stand For? All DEF Meanings Explained
DEF commonly refers to Diesel Exhaust Fluid, a fluid used in selective catalytic reduction (SCR) systems to reduce nitrogen oxide emissions from diesel engines.