Spanish nouns ending in nte (when they refer to people) can be used for both genders. However, with some of them, many Spanish speakers will change nte to nta when speaking about a woman.
Also, remember that the accompanying articles and adjectives must agree with the gender of the person we are talking about:
Juan es un adolescente terco.
Juan is a stubborn teenager.
Juana es una adolescente terca.
Juana is a stubborn teenager.
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