Slipped

He slipped on the wet steps and tumbled down the stairs.

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

She slipped on the rug and nearly fell down the stairs.

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

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

She slipped on the wet spot in the kitchen and dropped the dishes she was carrying.

The conversation with my boss slipped from my consciousness.

She slipped and made an error in her calculations, resulting in an incorrect answer.

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