Reflexive verbs in Hindi grammar are verbs that indicate the subject is performing an action upon itself. These verbs are used to express actions such as getting dressed, taking a bath, or thinking deeply. In Hindi, the reflexive pronoun “अपना” (apna) is used to indicate that the action refers to the subject of the sentence. Learning reflexive verbs is crucial for understanding and constructing sentences in Hindi, as they form an essential category of verbs in the language.