Slipped

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

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

The papers slipped out of the folder and scattered across the desk.

He slipped on the soap in the shower and grabbed onto the curtain to prevent falling.

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

He slipped on the wet tiles and almost crashed into the wall.

The key slipped out of the lock and onto the ground.

She slipped her feet into the high-heeled shoes, feeling confident and elegant.

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