sub

ot noun

1. A submarine sandwich: a sandwich made on a long bun. We can get subs at that deli.
2. A substitute, often in sports. She worked as a sub until she got her teaching certificate.
3. A subtitle. I've just noticed a mistake in the subs for this film.
4. A subscription (or (by extension) a subscriber) to an online channel or feed. I'm totally stoked; just got 10 new subs after my last video.

fe’l verb

1. To replace (a player) with a substitute. He never really made a contribution to the match, so it was no surprise when he was subbed at half time.
2. Less commonly, and often as sub on, to bring on (a player) as a substitute. He was subbed on half way through the second half, and scored within minutes.
3. To substitute for.
4. To work as a substitute teacher, especially in primary and secondary education.

predlog preposition

1. Under.