Infant

adj. of or pertaining to infants or infancy; being in infancy; baby, babyish; pertaining to a minor

n. baby, very young child, toddler, tot; minor; beginner

In basic English usage, an infant is defined as a human child at the youngest stage of life, specifically before they can walk and generally before the age of one (see also child and adolescent).The term "infant" derives from the Latin word in-fans, meaning "unable to speak." There is no exact definition for infancy. "Infant" is also a legal term with the meaning of minor; that is, any child under the age of legal adulthood.A human infant less than a month old is a newborn infant or a neonate. The term "newborn" includes premature infants, postmature infants and full term newborns.
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Infant /in·fant/ the human young from the time of birth to one year of age. dysmature infant postmature i. floppy infant see under syndrome. [more]Infant - Community and Resources

Noun
1. a very young child (birth to 1 year) who has not yet begun to walk or talk; "isn't she too young to have a baby?"
(synonym) baby, babe
(hypernym) child, kid
(hyponym) blue baby

(v. t.)
To bear or bring forth, as a child; hence, to produce, in general.
  

(n.)
Same as Infante.
  

(n.)
A person who is not of full age, or who has not attained the age of legal capacity; a person under the age of twenty-one years; a minor.
  

(n.)
A child in the first period of life, beginning at his birth; a young babe; sometimes, a child several years of age.
  

(a.)
Of or pertaining to infancy, or the first period of life; tender; not mature; as, infant strength.
  

(a.)
Intended for young children; as, an infant school.