1. To be worried or scared about something, frequently used to describe a drug-induced state of paranoia.

2. To vomit.

Origin: Great Grimsby. Possibly originally evolved from the word 'defecate', via 'shitting it'.
1. 'I'm deffing', 'She's deffin'-out', 'I deffed-out', 'Deff-out'

2. 'I just deffed'. 'He's deffin''.
by spacecaked March 15, 2011
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def /def/ adj. to describe a person, thing, or event that is cool. iarchaic, circa 1981/i
"yo, mah pizzles, I got da hook-up at this def new club. It's suppose ta be off da hizzy"
by Jay January 19, 2003
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Old skool version of low it meaning forget it, dont bother or dont even go there but in a nice kinda way
man sez 'bruv, shall we jack the offie'
man&man 'nah def it, its too on top'
by moi&dem January 15, 2007
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A short form for the word definetly.
"I'm defs keeping this on the DL."
"Are you going to John's tonight?" - "Defs."
by coolkidddd September 12, 2006
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It means like terrific or great or excellent
"I bet you were def." ~Fresh Prince Of Bel Air when he's talking to Ashley about her singing. 1st episode
by Lady_Rae_Marie January 11, 2006
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Slag for 'Deffinitly Not!'
"Wanna kiss my ass?" "Def Not!"
by Briggmyster June 16, 2006
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