Slipped

He slipped the pen off the desk and into his pocket.

She slipped on the spilled drink and spilled her own drink.

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

The restaurant's popularity has slipped due to poor customer service.

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

He slipped a piece of paper into the envelope and sealed it shut.

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

He slipped his backpack off his shoulder and onto the ground.