The Collaborative International Dictionary of English v.0.48:

lx \lx\ adj.
   the Roman numeral representation of sixty; six times ten;
   -- a determinate quantifier.

   Syn: sixty, 60, threescore.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

lx
    adj 1: being ten more than fifty [syn: sixty, 60, lx,
           threescore]
    n 1: the cardinal number that is the product of ten and six
         [syn: sixty, 60, LX]
    2: a unit of illumination equal to 1 lumen per square meter;
       0.0929 foot candle [syn: lux, lx]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

LX
       Linear eXecutable (OS/2)