The word 小偷 is formed by combining two characters: 小, meaning "small" or "petty", and 偷, meaning "to steal". Together, they create a compound that literally translates to "petty stealer". This construction directly conveys the concept of a common thief, one who commits minor thefts, as opposed to a large-scale robber, by simply and vividly describing the scale and action of the person.