Multimodal Nonverbal Decoding is a theoretical construct in nonverbal communication research that integrates and interprets congruent or incongruent affective, behavioral, and contextual cues from multiple sensory channels—such as facial expressions, vocal prosody, gestures, and body posture—to infer underlying emotional, cognitive, or interpersonal states, thereby extending unimodal decoding by accounting for interactive and synergistic cross-modal influences in naturalistic social interactions.