高祖 こうそ頭巾 ずきんであれば
gokōsozukindeareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 御高祖頭巾

1. If it were my great-great-great-grandfather's headcloth; If one were to wear my great-great-great-grandfather's headcloth

Ba Conditional