"Catch tripping" is a phrase that means to catch someone unaware or off-guard. There are several synonyms that can be used interchangeably with this phrase to convey the same meaning. For example, the phrase "catch off-guard" has the same connotation of surprising someone unexpectedly. Other synonyms for catch tripping include "take by surprise," "catch unawares," "startle," "shock," and "astonish." These words can be used effectively in various contexts, including everyday conversation, writing, and even literature. Regardless of which synonym is chosen, the overall message of taking someone by surprise or catching them off-guard remains the same.