Slipped

The spy slipped the secret code into the message, without anyone realizing it.

He slipped the key into the lock and turned it quietly.

She slipped out of her dress and into a swimsuit.

The secret plan was slipped into a confidential memo, without anyone noticing.

He slipped on the wet pavement and sprained his ankle.

The bag slipped off her shoulder and spilled its contents onto the sidewalk.

He slipped on the banana peel and landed on his backside.

She slipped on the icy sidewalk and slid several feet before coming to a stop.

He slipped out of his wet clothes and into a dry towel after a refreshing swim.

The spy slipped past the guard and entered the building undetected.