A son or daughter; child.
The definition of bairn is the Scottish term for a child.
An example of a bairn is a reference in a book when a Scottish character says they “have a dozen bairns,” which means a dozen children.
Origin of bairn
From Middle English barn, bern, from Old English (Anglian dialect) bearn (“child, son, descendant, offspring, issue, prodigy”) and Old Norse barn (“child”), both from Proto-Germanic *barną (“child”), from Proto-Indo-European *bʰer- (“to bear, bring forth”). Cognate with West Frisian bern (“child”), North Frisian baern, born (“child”), Middle High German barn (“child, son, daughter”), Swedish, barn (“child”), Norwegian barn (“child”), Icelandic barn (“child”), Albanian barrë (“pregnancy, child”). See also barn.