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

submergence \submer"gence\, n. from l. submergens, p. pr.
   the act of submerging, or the state of being submerged;
   submersion.
   1913 webster

[2] : WordNet (r) 2.0

submergence
     n : sinking until covered completely with water syn: submerging,
          submersion, immersion
see also:
submerging submersion immersion 

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

49 moby thesaurus words for "submergence":
   baptism, breaking water, burial, cadence, catenary, concavity,
   crash dive, de-escalation, debasement, decline, decurrence,
   degradation, demotion, depression, descent, detrusion, diminution,
   dip, dipping, displacement, dive, dousing, draft, droop, duck,
   ducking, dunking, engulfment, hauling down, hollowness, immergence,
   immersion, inundation, lapse, lowering, reduction, running dive,
   sag, sinkage, sinking, slump, souse, sousing, stationary dive,
   submersion, subsidence, surfacing, swag, thrusting under

Submergence >> S Words
Submergence, definition of term: Submergence
submergence_pag1.html