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 - Wikipedia
DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NO x) in the diesel exhaust emissions from a diesel engine.
Cambridge Dictionary: Find Definitions, Meanings & Translations
The most popular dictionary and thesaurus for learners of English. Definitions and meanings of words with pronunciations and translations.
def - Wiktionary, the free dictionary
Nov 17, 2025 · Failing to see the word's antecedents, I suspected that def was either bogus or an orphan, lost to its slang ancestors through mispronunciation or misspelling […]
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 - definition of def by The Free Dictionary
def Also found in: Thesaurus, Medical, Legal, Financial, Acronyms, Idioms, Encyclopedia, Wikipedia.
DEF Definition & Meaning | Dictionary.com
DEF definition: definitely. See examples of def used in a sentence.
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
1 day ago · Clear and simple definitions in American English from Britannica's language experts. More usage examples than any other dictionary.
Where to Find DEF at the Pump: Map and List of Stations
What is DEF? DEF stands for diesel exhaust fluid. It's a non-toxic, colorless, and odorless liquid used in modern diesel engines equipped with selective catalytic reduction (SCR) systems to …