Swaggering is the present participle of swagger (probably a frequentative of swag 'to sway, lurch', of Scandinavian origin, akin to Old Norse sveggja 'to sway') used adjectivally. Important recorded forms include sveggja (Old Norse). Morphologically, the ending or combining element adapts the older base to the present English part of speech while keeping the historical sense visible. The wording preserves that uncertainty: the older history is best read as a cautious account rather than a fully settled chain. The modern sense continues the older lexical line without requiring a separate origin. In current use it covers behaving or moving in an arrogantly confident, self-important way. The wider family includes related words such as swagger and swag.