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.

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

The building's safety standards have slipped over the years due to lack of maintenance.

The package slipped from the delivery driver's hands and tumbled down the steps.

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

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