(informal, transitive) To increase one's muscle mass.
She was bigged up—had a weight-lifter's rippling arms. 2007, David Handler, The Bright Silver Star: A Berger and Mitry Mystery:
(informal) To become big.
Relatively simple multicellular forms had already existed for a hundred million years when the Cambrian began: the explosion had a long fuse, and during this earlier fizzling life experimented with various ways to big up. 2012, Caspar Henderson, The Book of Barely Imagined Beings, page 83:
(slang, transitive) To behave confidently and proudly.
(slang, transitive) To proclaim or exaggerate the importance of; to promote.
I want to big up my bro on the mic.
Bradshaw bigs up local trades: "Agricultural produce, good cider and perry (which require a little brandy to qualify them), wool, hops, and prime cattle, - the last being a splendid breed, white-faced, with soft reddish-brown coats. [...]." 2022 August 24, Stephen Roberts, “Bradshaw's Britain: the Cotswold Line”, in RAIL, number 964, page 61:
Some say of me, "There's Adrian again in the media, bigging himself up. 2017, Daniel Tammet, Every Word is a Bird We Teach to Sing, →ISBN, page 162:
In a keynote speech, attended by over 2,000 people, Steve Jobs spent the first 10 minutes bigging up the move to Intel chips. 2007, Apple announces new mobile phone, BBC Online, 9 January 2007
They're trying to big themselves up to be more than they are.