Infantile

Origin

Mid-15th century, "pertaining to infants," from Latin infantilis "pertaining to an infant," from Latin infans. Sense of "infant-like" is from 1772.http://www.etymonline.com/index.php?term=infantile&allowed_in_frame=0

Full definition of infantile

Adjective

1. Pertaining to infants.infantile paralysis
• 1963, Margery Allingham, The China Governess Chapter 9, Eustace gaped at him in amazement. When his urbanity dropped away from him, as now, he had an innocence of expression which was almost infantile. It was as if the world had never touched him at all.
2. Childish; immature.

Synonyms

• (childish) puerile

Derived terms

• infantilely
• infantilize