Definition of down-low in English:

down-low

adjective

informal US
  • Discreet or secret.

    • ‘will James continue his down-low relationship with the high-profile surgeon?’

Phrases

    on the down-low
    • 1US informal On the quiet; in secret.

      • ‘he kept his status as a Hell's Angel on the down-low’
      1. 1.1(of a man) concealing his homosexual tendencies.

Origin

1990s originally in African American usage.