"deffos" means: Definitely.. This is informal slang, common in casual speech, texting and social media, but not appropriate for school work, applications or professional settings. There is no real cause for concern in itself; it is everyday peer vocabulary. If your child uses it, a light comment about audience and register is usually enough — no need to escalate. Context, more than the word, tells you whether to follow up.
deffos
(colloquial, chiefly, _, UK) Definitely.
Definitions
(colloquial, chiefly, _, UK) Definitely.
A quick peep out of the window confirmed I was not in Clerkenwell. 'Dead sure about it. I can see the sea and everything. Deffos in Hawaii.'
"deffos" means: Definitely.. This is informal slang, common in casual speech, texting and social media, but not appropriate for school work, applications or professional settings. There is no real cause for concern in itself; it is everyday peer vocabulary. If your child uses it, a light comment about audience and register is usually enough — no need to escalate. Context, more than the word, tells you whether to follow up.
"deffos" means: Definitely.. Register: informal slang, fine in casual conversation, texting and social media but not in academic essays, business writing or formal speech. Note the regional or dialect label (UK) — usage may sound odd outside that variety. A common non-native mistake is to use the word in the wrong register, or to assume one fixed meaning when it is actually polysemous; always check the surrounding register and the audience before producing it yourself. In formal writing, prefer a neutral synonym or a short descriptive phrase, and use this word only when you have heard or read it being used naturally in a comparable context.
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For specific readers
Why is this section here?
Slang is read by different audiences for very different reasons. The For parents view re-explains the term in plain, non-judgemental language so a caregiver can understand what their child means without needing the surrounding subculture. The For English learners view focuses on register (when it's safe to use), formal alternatives, and common mistakes — what a textbook won't teach you.
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🇬🇧About British & Irish slang slang
UK and Irish slang — Cockney, Scouse, Geordie, Yorkshire, Glaswegian, Brummie, Welsh, West Country, plus Irish English. Centuries of regional dialects feeding into modern British and Irish street talk.
See all British & Irish slang slang on Slangora.
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Other words near "deffos" (D)
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Semantically related
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Definitely. A short confirmation used in chats and replies, often standalone ("you in for Friday?" — "def"). Frequently extended to "defs" in younger British and Australian usage.
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Definitely. A casual variant of "def" with a tacked-on "s" that makes it feel lighter and chattier. Especially common in British, Australian and Irish texting style.
- 65%
(slang) For sure, definitely.
- 63%
(chiefly, Scotland) doubtless.
- 62%
(US, colloquial) Definitely not; no way.