start up

verb

1. To rise suddenly.

   “He started up when he heard the scream.”

2. To commence the operation of; to activate; to launch.

   “The four of them started up a law practice.”

3. To begin to operate.

   “The engine started up right away.”

4. To begin.

   “The band started up playing.”

5. To begin to make a sound

   “First a solitary blackbird started up, but soon the whole forest was alive with birdsong.”