The Collaborative International Dictionary of English v.0.48:

L \L\ ([e^]l), n.
   1. An extension at right angles to the length of a main
      building, giving to the ground plan a form resembling the
      letter L; sometimes less properly applied to a narrower,
      or lower, extension in the direction of the length of the
      main building; a wing. [Written also ell.]
      [1913 Webster]

   2. (Mech.) A short right-angled pipe fitting, used in
      connecting two pipes at right angles. [Written also
      ell.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

L \L\ ([e^]l) n.
   1. L is the twelfth letter of the English alphabet, and a
      vocal consonant. It is usually called a semivowel or
      liquid. Its form and value are from the Greek, through the
      Latin, the form of the Greek letter being from the
      Ph[oe]nician, and the ultimate origin prob. Egyptian.
      Etymologically, it is most closely related to r and u; as
      in pilgrim, peregrine, couch (fr. collocare), aubura (fr.
      LL. alburnus).
      [1913 Webster]

   Note: At the end of monosyllables containing a single vowel,
         it is often doubled, as in fall, full, bell; but not
         after digraphs, as in foul, fool, prowl, growl, foal.
         In English words, the terminating syllable le is
         unaccented, the e is silent, and l is preceded by a
         voice glide, as in able, eagle, pronounced [=a]"b'l,
         [=e]"g'l. See Guide to Pronunciation, [sect]241.
         [1913 Webster]

   2. As a numeral, L stands for fifty in the English, as in the
      Latin language.
      [1913 Webster]

            For 50 the Romans used the Chalcidian chi, ?, which
            assumed the less difficult lapidary type, ?, and was
            then easily assimilated to L.         --I. Taylor
                                                  (The
                                                  Alphabet).
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

L \L\, a.
   1. Having the general shape of the (capital) letter L; as, an
      L beam, or L-beam.
      [Webster 1913 Suppl.]

   2. Elevated; -- a symbol for el. as an abbreviation of
      elevated in elevated road or railroad. -- n. An elevated
      road; as, to ride on the L. [Colloq., U. S.]
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

l
    adj 1: being ten more than forty [syn: fifty, 50, l]
    n 1: a metric unit of capacity, formerly defined as the volume
         of one kilogram of pure water under standard conditions;
         now equal to 1,000 cubic centimeters (or approximately 1.75
         pints) [syn: liter, litre, l, cubic decimeter,
         cubic decimetre]
    2: the cardinal number that is the product of ten and five [syn:
       fifty, 50, L]
    3: a cgs unit of illumination equal to the brightness of a
       perfectly diffusing surface that emits or reflects one lumen
       per square centimeter [syn: lambert, L]
    4: the 12th letter of the Roman alphabet [syn: L, l]

Moby Thesaurus II by Grady Ward, 1.0:

162 Moby Thesaurus words for "L":
   R, Sexagesima, acting area, addition, angle, annex, apex, apron,
   apron stage, backstage, band shell, bandstand, bend, bifurcation,
   bight, board, boxcar, boxcars, branch, bridge, cable railway, cant,
   chevron, cog railway, coin, corner, coulisse, crank, crook,
   crotchet, deflection, dock, dogleg, dozen, dressing room,
   duodecimo, eighty, el, elbow, electric railway, elevated,
   elevated railway, eleven, ell, embankment, extension, feeder,
   feeder line, fifteen, fifty, five and twenty, flies, fly floor,
   fly gallery, forestage, fork, fortnight, forty, four and twenty,
   fourscore, fourscore and ten, fourteen, furcation,
   gravity-operated railway, greenroom, grid, gridiron,
   half a hundred, hook, horse railway, inflection, junction, knee,
   light railroad, lightboard, line, long dozen, main line, metro,
   monorail, ninety, nonagenarian, nook, octogenarian, orchestra,
   orchestra pit, performing area, pit, point, proscenium,
   proscenium stage, quindecennial, quindecim, quindecima, quindene,
   quoin, rack railway, rack-and-pinion railway, rail, rail line,
   railroad, railway, roadbed, roadway, score, septuagenarian,
   seventy, sexagenarian, sexagenary, sexagesimo-quarto, shell,
   sidetrack, siding, sixteen, sixteenmo, sixty, sixty-four,
   sixty-fourmo, stage, stage left, stage right, street railway,
   streetcar line, subway, swerve, switchback, switchboard, teens,
   terminal, terminus, the boards, thirteen, thirty-two, thirty-twomo,
   threescore, threescore and ten, track, tram, tramline, trestle,
   trolley line, trunk, trunk line, tube, turnout, twelve, twelvemo,
   twenty, twenty-five, twenty-four, twenty-fourmo, two dozen,
   two weeks, twoscore, underground, veer, vertex, wing, wings, zag,
   zig, zigzag