てっする
tessuru

Suru Verb

1. to penetrate; to sink in

Intransitive
Suru Verb

2. to devote oneself (to); to do intently and exclusively

Intransitive
大学 だいがく たての新人 しんじん資料 しりょう つくったり、コピーをとったりと裏方 うらかた仕事 しごと てっするのだろうと、勝手 かって想像 そうぞうしていたのですが見事 みごと裏切 られました。
daigakudetateno shinjinwa shiryōo tsukuttari kopiio tottarito urakatashigotoni tessuru nodarōto katteni sōzō shite ita nodesuga migotoni uragiraremashita.
I had imagined that the newbies fresh from university would probably be stuck with all the backstage work - collecting reference material, getting copies and such but I couldn't have been proved more wrong.
Suru Verb

3. to do throughout (e.g. the night)

Intransitive
よる てっするか いなか。
yoruo tessuruka hika
Should I stay up all night or not?