Continuing the look at synonyms through the eyes of the etymologist, this time it is the letter K and kid. Hardly any surprise to find this began as the young of the goat, its etymology is uncertain, and later applied to children, first recorded in 1590.
Child is first seen in Old English cild where it referred to the unborn infant or foetus. It came from Proto-Germanic kiltham, a word which also gave Gothic kilpei 'womb' and inkilpo 'pregnant'. Note the Old Swedish kulder was used to mean 'litter', while Old English cildhama may have been defined as 'womb' but actually was literally 'child home', and in the 15th and 17th centuries 'child' was nearly always referring to a girl.
Baby is a diminutive of 'babe', itself short for the 13th century word baban and likely imitative of baby talk (as is 'babble').
Toddler is derived from 'toddle', a word first seen in Scotland and northern England and of unknown origin.
Infant is an interesting word which is a combination of 'in' and 'fari'. Here 'in' is used as a prefix meaning 'not', while 'fari' is the verb 'to speak'. A pretty good description of a young infant.
Minor began as a Latin word meaning 'small', and is derived from the Proto-Indo-European root mei also meaning 'small'.
Juvenile is from the Latin iuvenilis meaning 'youthful'. It came from iuvensis 'young man, one in the flower of his age'. Note this did not refer to one who was just maturing, or approaching maturity, for the Romans this was a man aged between 21 and 40 - there's hope for us yet.
Youth is, unsurprisingly, from the same source as 'young' and yet 'youth was the earlier word. Another of Germanic origins, it was more often used to refer to young warriors and even the young of cattle in its earliest times.
Teenager is named from those in their teens (thirteen, fourteen, fifteen, etc.). Teenager has only ben used since 1922, prior to that it was 'teener', and earlier still simply 'teen'.Note the element 'teen' is from 'ten' - this fourteen is four-ten, sixteen is six-ten, and so on.