[1] : WordNet (r) 2.0

light up
     v 1: start to burn with a bright flame; "the coal in the bbq
          grill finally lit up"
     2: make lighter or brighter; "this lamp lightens the room a
        bit" syn: light, illume, illumine, illuminate
     3: become clear; "the sky cleared after the storm" syn: clear
        up, clear, brighten ant: overcast
     4: ignite; "the sky lit up quickly above the raging volcano"
     5: begin to smoke; "after the meal, some of the diners lit up"
        syn: fire up, light
see also:
light illume illumine illuminate clear up clear 
brighten overcast fire up 

[2] : Moby Thesaurus II by Grady Ward, 1.0

93 moby thesaurus words for "light up":
   annoy, arouse, awake, awaken, bank, beacon, blow the coals,
   blow up, brace up, brighten, brighten up, buck up, burn,
   call forth, call up, cheer up, chirk up, conflagrate, enkindle,
   enlighten, enrage, excite, fan, fan the fire, fan the flame, feed,
   feed the fire, fire, flame, flood with light, floodlight, foment,
   frenzy, heat, highlight, ignite, illume, illuminate, illumine,
   impassion, incense, incite, inflame, infuriate, irradiate, key up,
   kindle, lather up, light, light the fuse, lighten, luminate,
   madden, move, overexcite, overshine, perk up, rekindle, relight,
   relume, relumine, revive, rouse, set astir, set fire to,
   set on fire, shed light upon, shine upon, spotlight, steam up,
   stir, stir the blood, stir the embers, stir the feelings,
   stir the fire, stir up, stoke, stoke the fire, strike a light,
   summon up, take heart, throw light upon, torch, touch off, turn on,
   wake, wake up, waken, warm, warm the blood, whip up, work into,
   work up

Backed Up >> B Words
Backed Up, definition of term: Backed Up
backed+up_pag1.html

Ball Up >> B Words
Ball Up, definition of term: Ball Up
ball+up_pag1.html

Back Up >> B Words
Back Up, definition of term: Back Up
back+up_pag1.html

Arc Light >> A Words
Arc Light, definition of term: Arc Light
arc+light_pag1.html

Ante Up >> A Words
Ante Up, definition of term: Ante Up
ante+up_pag1.html

Act Up >> A Words
Act Up, definition of term: Act Up
act+up_pag1.html