to put (something) in a liquid for a period of time
Steep the tea for three minutes.
The tea steeped for five minutes.
steep in (phrasal verb)
1 steep (someone) in (something) : to make (someone) know and understand a lot about (something)
Prior to his trip, he spent a few weeks steeping himself in the language. (=learning a lot about the language)
— often used as (be) steeped in
She was steeped in the classics. (=she had learned a lot about the classics)
2 — used as (be) steeped in to say that there is a lot of something in a place, time, etc.
an area steeped in history (=an area where many important historical events occurred)
It was a time in the nation’s history that was steeped in bloodshed. (=a time when there was a lot of bloodshed)