Green’s Dictionary of Slang

1. (also big oneself up, big up one’s chest) to act in a proud, self-confident manner.

1953		R. Mais Hills were Joyful Together (1966) 72: An’ Ditty she a big gal now caan help her [...] but ah-so today pickney stay, me Jesus, gal ah big-up like ooman now scasely can kip de one-room clean.
1995		Francis-Jackson Official Dancehall Dict. 8: Big up yuh chest to assume an air of importance. [...] Big up yuhself enjoy your status, you’ve earned it.
1997		N. Barlay Curvy Lovebox 30: In front of me he can big himself up all he likes.
2002		‘Touré’ Portable Promised Land (ms.) 157: We Words (My Favorite Things) [...] Souped up. Straight up. Step up. Big up.

2. (UK black) to promote, to boost, to praise.

1991		Tony Rebel ‘Sweet Jamaica’ 🎵 Help me big up Jamaica.
1995		G. Small Ruthless 385: Instead of ‘running them’ [chasing them away], the youth ‘bigged them up’ [flattered them]; they gave them respect.
1998		Source Oct. 35: I also wanted to do a song biggin’ up women because they’re very strong.
2001		Source Aug. 100: We’re just bigging up the South in general.
2006		G. Malkani Londonstani (2007) 64: I in’t makin all this up just to big Samira up.
2012		Jamaica Star 18 May 🌐 Me a play Ryno song dem an even a big him upon di mic, and him a big mi up too.
2012		‘Dutch’ ? (Pronounced Que) [ebook] [The media] never miss an opportunity to big-up the police.
2018		Guardian 25 Jan. 2/2: This was a testosterone-fuelled, dick-swinging [...] slimeball night out [...] abusing women to big-up male entitlement.

3. (W.I./UK black teen) to greet friends, to pay tribute to something or someone big or important, e.g. Big up the dancehall crew dem, seen, come again.

1997		C. Newland Scholar 130: ‘I’m gettin’ some for you anyway, so eat what you want, leave what you want, innit?’ ‘Big up, respec’, star.’.
2000		Guardian Guide 1–6 Jan. 18: Big up everyone who went clubbing on NYEY2K.
2005		DJ Cameo on 1Xtra [BBC radio] Big up Johnny B.
2010		Popcorn ‘Dem Sell We Out’ 🎵 Big up, Jah Vinci, me bredder.

4. to boast.

2011

G. Knight Hood Rat 108: If one of them was merked, they would all big up how they were going to kill other people.