秘密にする。口外しない。⇒ down low
"keep it secret/keep it on down low."
To keep quite on something. To not tell people about something. /
To not divulge information to people that should not know about something. /
Keeping certain information limited to a certain group or between two people.(ある事を一部の人だけの胸に留めて置く事）
"Keep this shit on the down low for now."
"bad pitch that looked like it would miss down low"