Meaning

adjective designating the generation or the sequence of generations following the parental generation

adjective relating to or characteristic of or befitting an offspring

originEtymology tree Proto-Indo-European *dʰeh₁(y)- Proto-Indo-European *-yós Proto-Indo-European *dʰh₁ilyós Proto-Italic *θīlios Proto-Italic *fīlios Latin fīlius Proto-Indo-European *h₂el-der.? Proto-Italic *-ālis Latin -ālis Latin fīliālisder. Middle English filial English filial From Middle English filial, from Latin fīliālis, from filius (“son”) / filia (“daughter”) + -al.

Etymology from Wiktionary, CC BY-SA 3.0