Refers to one's outward appearance, especially clothing and overall look. Often used in literary or formal contexts. Similar to なりふり (形振り) but less common.
See also: なりふり
His appearance is always neat.
Please come dressed appropriately for the occasion.
Compound of 形 (なり, 'form, shape') and 姿 (すがた, 'figure, appearance'). The reading なりすがた is a straightforward combination of the kun'yomi readings of the two kanji.