To trawl, the act or art of trawling.
The pub or bar is about to shut, you havent picked up yet so you "trawl" the room to see what girls are still availible. Sometimes you might have to do some deepsea trawling and might end up with a shocker, it all relates to how strong your beer goggles are.

the thing that you don’t have when you’re phones percentage is over 20

A strategy used on the Plenty Of Fish online dating website where the user creates a generic message, copies and pastes it to as many people as possible in order to get as many replies as possible. Similar to ocean trawling in that it is used to get a large quantity and have the quality sorted out later.

To walk around with your dick hanging out, as if to use it to trawl for something.