Declension

n.	1.	The act or the state of declining; declination; descent; slope. The declension of the land from that place to the sea. - T. Burnet.
	2.	A falling off towards a worse state; a downward tendency; deterioration; decay; as, the declension of virtue, of science, of a state, etc. Seduced the pitch and height of all his thoughts To base declension. - Shak.
	3.	Act of courteously refusing; act of declining; a declinature; refusal; as, the declension of a nomination.
	4.	(Gram.) Inflection of nouns, adjectives, etc., according to the grammatical cases. Declension of the needle declination of the needle.

Noun	1.	declension - the inflection of nouns and pronouns and adjectives in Indo-European languages
	2.	declension - process of changing to an inferior state Synonyms: decline in quality, worsening, deterioration
	3.	declension - a downward slope or bend Synonyms: declivity, downslope, declination, decline, fall, descent
	4.	declension - a class of nouns or pronouns or adjectives in Indo-European languages having the same (or very similar) inflectional forms; "the first declension in Latin"

IC analysis, abnegation, accidence, affix, affixation, allomorph, bound morpheme, cascade, catabasis, cataract, chute, collapse, comedown, conjugation, contradiction, crash, cutting, debacle, debasement, decadence, decadency, deceleration, declination, declinature, decline, decline and fall, declining, decrescendo, defluxion, deformation, degeneracy, degenerateness, degeneration, degradation, demotion, denial, depravation, depravedness, depreciation, deprivation, derivation, derogation, descending, descension, descent, deterioration, devolution, difference of form, dilapidation, diminuendo, disagreement, disallowance, disclaimer, disclamation, disobedience, dissent, dive, down, downbend, downcome, downcurve, downfall, downflow, downgrade, downpour, downrush, downtrend, downturn, downward mobility, downward trend, drop, dropping, dwindling, dying, ebb, effeteness, enclitic, fading, failing, fall, falling, falling-off, formative, free form, gravitation, holding back, immediate constituent analysis, inclination, infix, infixation, inflection, involution, lapse, loss of tone, morph, morpheme, morphemic analysis, morphemics, morphology, morphophonemics, nay, negation, negative, negative answer, nix, no, nonacceptance, noncompliance, nonconsent, nonobservance, paradigm, plummeting, plunge, pounce, prefix, prefixation, proclitic, radical, rapids, recantation, refusal, regression, rejection, remission, repudiation, retention, retreat, retrocession, retrogradation, retrogression, root, ruination, slippage, slowdown, slump, stem, stoop, subsidence, suffix, suffixation, swoop, theme, thumbs-down, turndown, unwillingness, wane, waterfall, withholding, word-formation