I first came across "loblolly" in the Bloody Jack series of books, by L.A. Meyer.

Jacky Faber is an orphan and street urchin in London, circa 1803. After volunteering to be a ship's boy in the Royal Navy life gets better. One problem: Jacky is a girl and has to find a way of hiding her gender from the other ship's boys and the officers of The Dolphin. In one of the books she meets a ship's loblolly.

I loved these adventure books and can particularly recommend the audio versions with reader Katherine Kellgren.

Most unfortunately, author Meyer died just a few weeks ago.

You can read about the series here: Bloody Jack.