The Collaborative International Dictionary
Loblolly \Lob"lol`ly\, n. [Etymol. uncertain.] Gruel; porridge; -- so called among seamen.
Loblolly bay (Bot.), an elegant white-flowered evergreen shrub or small tree, of the genus Gordonia ( Gordonia Lasianthus), growing in the maritime parts of the Southern United States. Its bark is sometimes used in tanning. Also, a similar West Indian tree ( Laplacea h[ae]matoxylon).
Loblolly boy, a surgeon's attendant on shipboard.
--Smollett.
Loblolly pine (Bot.), a kind of pitch pine found from Delaware southward along the coast; old field pine ( Pinus T[ae]da). Also, Pinus Bahamensis, of the West Indies.
Loblolly tree (Bot.), a name of several West Indian trees, having more or less leathery foliage, but alike in no other respect; as Pisonia subcordata, Cordia alba, and Cupania glabra.
Wiktionary
n. (context historical English) in 18th and 19th century warships, a non-professional assistant to the ship's surgeon.
Wikipedia
A loblolly boy on a warship was an assistant to the ship's surgeon. In Tobias Smollett's 1748 novel The Adventures of Roderick Random, the first to describe Royal Navy life in detail, the protagonist Random was made a loblolly boy upon entering the Royal Navy, and ultimately received his warrant as a surgeon's mate. Loblolly boys also appear in C. S. Forester's Horatio Hornblower novels, Alexander Kent's "Midshipman Bolitho" novels, and Patrick O'Brian's Aubrey-Maturin novels. Stephen Maturin's loblolly boy, Padeen, features in several of O'Brian's books.
Possibly because of such influential media representations, it is sometimes erroneously thought to be solely a Royal Navy rating, and surgeons' assistants were so styled in the Royal Navy by 1597. The rating was also used in U.S. Navy warships from the late 18th century until 1861, when the name surgeon's steward was introduced to reflect more stringent training requirements. The name was changed to apothecary in 1866, and again in the 1870s to bayman and then in the early 20th century to Hospital Corpsman. The Royal Navy name changed to sick berth attendant in 1833, with the nickname Sick Bay Tiffy (Tiffy being slang for Artificer) gaining popularity in the 1890s. Medical Assistant is the current term.
The name itself comes from the serving of loblolly – a thick porridge, sometimes enhanced with chunks of meat or vegetables — to sick or injured crewmembers to hasten their recovery. Loblolly, in turn, probably comes from the fusion of lob, a Yorkshire word meaning to boil or bubble, and lolly, an archaic English word for a stew or soup. Loblolly itself eventually came to mean anything viscous, such as a swamp or bog, and terms such as the Loblolly pine were coined from the muddy habitat of the tree rather than from any culinary use.
The loblolly boy's duties included serving food to the sick, but also undertaking any medical tasks that the surgeon was too busy (or too high in station) to perform. These included restraining patients during surgery, obtaining and cleaning surgical instruments, disposing of amputated limbs, and emptying and cleaning toilet utensils. The loblolly boy also often managed stocks of herbs, medicines and medical supplies.