down low

• down-low
• downlow

down low (uncountable)

1. A state of secrecy.

   I'll tell you, but keep it on the down low.

2. (sexuality) The state of being a man who secretly sleeps with people other than his partner.
3. (African American Vernacular, sexuality) The state of being a man who secretly sleeps with other men.

• In all senses, always preceded by on the.

down low (comparative more down low, superlative most down low)

1. (of a person) Undercover or lying about one's identity.
2. (African American Vernacular, of a man) Purporting to be heterosexual while engaged in sex with men.

• DL

• low-down, lowdown