"Pull someone's leg" is an idiomatic expression that means to tease or play a practical joke on someone. There are various synonyms for this phrase, including "joking around," "tease," "kid," "fool around with," or even "mess with someone." Other words that are associated with this phrase are "ribbing," meaning good-natured teasing; "banter," a playful and humorous exchange of remarks; and "prank," referring to a mischievous trick or practical joke. No matter the words used, pulling someone's leg is a lighthearted way to playfully tease someone, making them laugh and smile.