Green’s Dictionary of Slang

1. (US black) on one’s own, solo.

1991		Tribe Called Quest ‘Check the Rhime’ 🎵 See, my shit is universal if you got knowledge of dolo.
1993		Lerner et al. Dict. of Today’s Words.
2002		‘Touré’ Portable Promised Land (ms.) 156: We Words (My Favorite Things) [...] Mambo. Mofo. Mojo. Dolo. Gumbo. Gusto.
2011		Snoop Dogg & Wiz Khalifa ‘World Class’ 🎵 Solo, creepin on the dolo, tippin like a low-low.

2. (US campus) secret.

1999

Eble Campus Sl. Apr. 2: do lo – secret. From down low.