Have It Large Meaning

(idiomatic) To engage intensely in pleasure-seeking activities

Example: 1999, Mick Middles, Manic Street Preachers, page 193
  Unlike Oasis, the point wasn't simply to have it large and live a whacked-out existence as professional rock stars.
1999, Jeremy Gilbert, Ewan Pearson, Discographies: Dance Music, Culture, and the Politics of Sound, page 28
  […] that cultural theorists could be forgiven for thinking that every young Briton between the ages of 15 and 25 was out having it large.
2006, Bill Sanders, Drugs, Clubs And Young People: Sociological and Public Health Perspectives, page xi
  On the dance floor, people are having it large: hands in the air, whooping and yelling, boogieing in a sweaty drug fueled mass.