せちゃう
uchiyosechau

Ichidan Verb
Godan Verb (u)

The completive aspect (contracted form) - indicates completion or regret of 打ち寄せる

1. Wash up (on the shore); Rush over; Come crashing down; ; Regretfully wash up; Regretfully rush over; Regretfully come crashing down

Completed Action
Colloquial