The Collaborative International Dictionary of English v.0.48:

Loblolly \Lob"lol`ly\, n. [Etymol. uncertain.]
   Gruel; porridge; -- so called among seamen.
   [1913 Webster]

   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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

loblolly pine
    n 1: tall spreading three-needled pine of southeastern United
         States having reddish-brown fissured bark and a full bushy
         upper head [syn: loblolly pine, frankincense pine,
         Pinus taeda]