What is another word for "declension"?

Roget's Thesaurus (1911) lists these synonyms for "declension": abate, abatement, abridge, abridgment, accidence, and, anticlimax, attenuate, away, bate, case, coarctation, conjugation, contract, contraction, correct, crumble, decay, decline, decrease, decreasing, decrement, depreciate, depreciation, dequantitate, descend, descent, deterioration, die, diminish, diminution, discount, drop, dwarf, ebb, extenuate, extenuation, fall, fine, fritter.