[1] : The Collaborative International Dictionary of English v.0.48

falling \fall"ing\, a.  n.
   from fall, v. i.
   1913 webster

   falling away, falling off, etc. see to fall away, to
      fall off, etc., under fall, v. i.

   falling band, the plain, broad, linen collar turning down
      over the doublet, worn in the early part of the 17th
      century.

   falling sickness med., epilepsy. --shak.

   falling star. astron. see shooting star.

   falling stone, a stone falling through the atmosphere; a
      meteorite; an a"erolite.

   falling tide, the ebb tide.

   falling weather, a rainy season. colloq. --bartlett.
      1913 webster
see also:
fall falling away falling off to fall away to fall off falling band 
falling sickness falling star shooting star falling stone falling tide 
falling weather 

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

109 moby thesaurus words for "falling sickness":
   jacksonian epilepsy, ms, rolandic epilepsy, abdominal epilepsy,
   access, acquired epilepsy, activated epilepsy, affect epilepsy,
   akinetic epilepsy, amyotrophic lateral sclerosis, apoplexy, arrest,
   attack, autonomic epilepsy, blockage, brain disease,
   cardiac epilepsy, cephalalgia, cerebral palsy, chorea,
   clonic spasm, clonus, convulsion, cortical epilepsy, cramp,
   cursive epilepsy, diurnal epilepsy, eclampsia, emotional disorder,
   epilepsia, epilepsia gravior, epilepsia major, epilepsia minor,
   epilepsia mitior, epilepsia nutans, epilepsia tarda, epilepsy,
   epitasis, fit, focal epilepsy, frenzy, glossopharyngeal neuralgia,
   grand mal, grip, haute mal, headache, herpes zoster,
   hysterical epilepsy, ictus, ischialgia, larval epilepsy,
   laryngeal epilepsy, laryngospasm, latent epilepsy, lockjaw,
   matutinal epilepsy, menstrual epilepsy, migraine,
   multiple sclerosis, musicogenic epilepsy, myoclonous epilepsy,
   nervous disorder, neuralgia, neuritis, neuropathy,
   nocturnal epilepsy, occlusion, organic psychosis, orgasm, palsy,
   paroxysm, petit mal, physiologic epilepsy, polyneuritis,
   pressure neuropathy, priapism, psychic epilepsy,
   psychomotor epilepsy, radiculitis, reflex epilepsy, rotatoria,
   sciatic neuritis, sciatica, seizure, sensory epilepsy,
   serial epilepsy, sexual climax, shaking palsy, shingles, spasm,
   spastic paralysis, stoppage, stroke, tardy epilepsy, tetanus,
   tetany, the jerks, throes, thromboembolism, thrombosis,
   tic douloureux, tonic epilepsy, tonic spasm, torsion spasm,
   toxic psychosis, traumatic epilepsy, trismus, ucinate epilepsy,
   visitation

Sickness >> S Words
Sickness, definition of term: Sickness
sickness_pag1.html

Falling >> F Words
Falling, definition of term: Falling
falling_pag1.html

Falling Star >> F Words
Falling Star, definition of term: Falling Star
falling+star_pag1.html

Green Sickness >> G Words
Green Sickness, definition of term: Green Sickness
green+sickness_pag1.html

Motion Sickness >> M Words
Motion Sickness, definition of term: Motion Sickness
motion+sickness_pag1.html