The Collaborative International Dictionary of English v.0.48:

Poplar \Pop"lar\, n. [OE. popler, OF. poplier, F. peuplier, fr.
   L. populus poplar.] (Bot.)
   1. Any tree of the genus Populus; also, the timber, which
      is soft, and capable of many uses.
      [1913 Webster]

   Note: The aspen poplar is Populus tremula and Populus
         tremuloides; Balsam poplar is Populus balsamifera;
         Lombardy poplar (Populus dilatata) is a tall, spiry
         tree; white poplar is Populus alba.
         [1913 Webster]

   2. The timber of the tulip tree; -- called also white
      poplar. [U.S.]
      [1913 Webster]

The Free On-line Dictionary of Computing (17 December 2009):

Poplar

   Morris, 1978.  A blend of LISP with SNOBOL4 pattern matching
   and APL-like postfix syntax.  Implicit iteration over lists,
   sorting primitive.  "Experience with an Applicative
   String-Processing Language", J.H. Morris et al, 7th POPL, ACM
   1980, pp.32-46.


Easton's 1897 Bible Dictionary:

Poplar
Heb. libneh, "white", (Gen. 30:37; Hos. 4:13), in all
probability the storax tree (Styrax officinalis) or white
poplar, distinguished by its white blossoms and pale leaves. It
is common in the Anti-Libanus. Other species of the poplar are
found in Palestine, such as the white poplar (P. alba) of our
own country, the black poplar (P. nigra), and the aspen (P.
tremula). (See WILLOW.)

U.S. Gazetteer (1990):

Poplar, MT (city, FIPS 58975)
  Location: 48.11029 N, 105.19589 W
  Population (1990): 881 (390 housing units)
  Area: 0.7 sq km (land), 0.0 sq km (water)
  Zip code(s): 59255
Poplar, WI (village, FIPS 63975)
  Location: 46.58193 N, 91.78780 W
  Population (1990): 516 (203 housing units)
  Area: 30.9 sq km (land), 0.0 sq km (water)
  Zip code(s): 54864