There are multiple definitions - click on the translation that matches your context.

menor de idade

substantivo

full

infant

noun

Definitions of infant

English

a baby or young child

A woman who police believe threw her infant daughter to her death from a window of a New York City apartment building has been arrested.

English

a minor (=someone who is too young to have the legal responsibilities of an adult)

The provisions protecting the importance of the family unit within the United Nations Declaration on the Rights of a Child must be evident within provincial laws that include any statute involving infant children.