dry powder

noun3

1. •
   A powder found in a fire extinguisher that is expelled to smother the fire (in contrast with liquid types of extinguisher).
2. •
   Cash (or cash-like securities) kept in reserve in case of need.

   • Private equity firms were sitting on more than $1 trillion in dry powder at the end of 2011.
3. •
   A powder found in an inhaler that delivers a bronchodilator for antiasthmatic or antiemphysemic purposes (indications).