The word 偷窃 is formed by combining two characters, 偷 and 窃, which both independently carry the core meaning of "to steal". This is a classic example of semantic compounding, where two synonyms or near-synonyms are joined to create a single, more precise or formal term. 偷 often emphasizes the stealthy, furtive action of stealing, while 窃 conveys the broader, more abstract concept of theft as a wrongful taking. Together, they reinforce and complete each other's meaning, resulting in a comprehensive word for "theft" that is more formal and legally concrete than either character used alone.