The phrase "as a defining trait" is correct and usable in written English.
It can be used to describe a characteristic that is essential or fundamental to someone or something.
Example: "Her ability to empathize with others is often seen as a defining trait of her leadership style."
Alternatives: "as a key characteristic" or "as a fundamental quality."
Over the years people have framed his Spanishness as a defining trait.
While Samus is a good character in many ways -- strong, independent, agile, intelligent -- the emphasis placed on her gender as a defining trait or "surprise" has sometimes raised eyebrows.
However, with the advent of second wave feminism, lesbian as a political identity grew to describe a social philosophy among women, often overshadowing sexual desire as a defining trait.
Integration as a defining trait of orbitofrontal function.
In the early studies on entrepreneurs, McClelland (1965) did claim the achievement drive as a defining trait of entrepreneurs.
Cafes turn out to be places where people can take a break from social pressure and express one's individuality outside the harmonious consensus that many perceive as a defining trait of Japanese culture.
What does the scissor shot have to do with the Federer gap? Flash is wonderful as long as it's not a defining trait.
Nineteenth-century writers often treated region as a defining cultural trait, one so fixed it rivaled biology in determining destiny.
But researchers will probably think twice before they use upright walking as their main defining trait for identifying a very early hominid that was still in the earliest stages of becoming bipedal.
The obsession with burial and what to do with bodies when life has fled is a defining human trait, as much a subject of poetry and epic as love or jealousy or war.
Predation and sporulation are common features of previously characterized myxobacteria and these functions were used as defining traits for the taxon [32].
