[ていか, teika] (n, vs) fall; decline; lowering; deterioration; degradation; (P) #3858
[あっか, akka] (n, vs, adj-no) (suffer) deterioration; growing worse; aggravation; degeneration; corruption; (P) #4916
[れっか, rekka] (n, vs) deterioration; degradation; drop in quality; (P) #14315
[かいあく, kaiaku] (n, vs) deterioration; changing for the worse
[きゅうてんあっか, kyuuten'akka] (n, vs) suddenly turning for the worse; sudden deterioration
[けいねんれっか, keinenrekka] (n, vs) degradation over time; time-related deterioration
[たいはい, taihai] (n, vs, adj-no) degeneration; decadence; deterioration; laxness; corruption; (P)
[ふきゅう, fukyuu] (n, vs) deterioration; rot
[へんしつ, henshitsu] (n, vs, adj-no) alteration (of character or essence); change in quality; transformation; deterioration; degeneration; transmutation; (P)
[ろうか, rouka] (n, vs, adj-no) ageing; aging; senile deterioration; (P)
[ろうきゅうか, roukyuuka] (n, vs) aging; wearing out; deterioration