高祖 こうそ頭巾 ずきんでしょう
gokōsozukindeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 御高祖頭巾

1. Probably your great-great-grandfather's head covering.; Possibly a head covering from your ancestor.

Polite
Presumptive
Conjecture