English

fullsib

From full + sib.

A compound of full + sib

Proto-Indo-European *pleh₁- ‘to fill’

…

Proto-Germanic *fullaz ‘full’

Proto-West Germanic *full ‘full’

Old English full ‘full’

Middle English ful ‘full’

English full

Proto-Indo-European *sebʰ-

Proto-Germanic *sibjaz ‘related’

Old English sibb ‘related, akin, sib’

Middle English sib

English sib

Today it means

noun A full sibling.

Language periods are conventional ranges, not dates for this word.