The verb 'strut' originates from a Middle English term describing a stiff, rigid, or swollen posture. This core sense of stiffness and protrusion evolved metaphorically to describe a stiff, proud, and often arrogant manner of walking, as if one's body is puffed up with self-importance. The addition of the '-ing' suffix, a productive grammatical element from Old English, transforms the action into an adjective describing the manner of walking or a noun denoting the act itself. Thus, 'strutting' literally captures the image of walking with a stiff, swollen, and ostentatious pride.

Structure: strut (to walk stiffly) + ing (present participle/gerund suffix) - strut: From Middle English strouten, meaning "to bulge, swell, stand out stiffly." Likely from a Proto-Germanic root related to stiffness and rigidity. Its functional role is the core verb/action. - ing: From Old English -ende (present participle) and -ung (verbal noun). Its functional role is to form the present participle (adjective) or gerund (noun) from the verb.