Noun has 2 senses

• dissimilation(n = noun.process) - a linguistic process by which one of two similar sounds in a word becomes less like the other; "the Old French MARBRE became the English MARBLE by dissimilation"

Derived form verb dissimilate₁, verb dissimilate₃

• dissimilation(n = noun.process) catabolism, destructive metabolism, katabolism - breakdown in living organisms of more complex substances into simpler ones together with release of energy;