Ahoy! Abaft is a word used on boats. If something is abaft, it’s towards the rear, or stern, of a boat. Abaft means "in the back."
Though rarely heard on dry land, this old seafaring word refers to the rear end of a ship. Abaft can also refer to the back end of an airplane. Even if you’re not a sailor (or pilot), if you read Moby Dick or other stories of the sea, then you’ll need to know what abaft means. Think of the word after when you see that aft on the end.