The expression, which apparently had the original spelling “hookey,” is commonly used to express missing some scheduled event without permission. Mark Twain used it to describe how Tom Sawyer “took his flogging, along with Joe Harper, for playing hookey the day before.” The Urban Dictionary says the term is probably derived from the Dutch term “hoekje” for the game of hide and seek based on the word “hoek,” which means corner. The expression evolved into playing hooky to describe children skipping school. There is an alternative origin based on the verb hook meaning “to steal.” However, “hook it” didn’t make it into common use until playing hooky was already in use.