What word or phrase does your mother always say?
late 15c., "shot, missiles;" later "a stroke, short line" (1580s), from Middle French trait, from Latin tractus "draft, drawing, drawing out," later "line drawn, feature," from past participle stem of trahere "to pull, draw" (see tract (n.1)). Sense of "particular feature, distinguishing quality" is first recorded 1752, from meaning "line, streak, feature" (1560s), which is common to English, French, and Latin.
A characteristic, especially one that distinguishes an individual from others.
A genetically determined characteristic or condition. Traits may be physical, such as hair color or leaf shape, or they may be behavioral, such as nesting in birds and burrowing in rodents. Traits typically result from the combined action of several genes, though some traits are expressed by a single gene.