Natyashastra
अत्र शुष्काक्षरैरेव ह्यवकृष्टा ध्रुवा यतः । तस्माच्छुष्कावकृष्टेयं जर्जरश्लोकदर्शिता ॥ २५॥
Here, it is firmly established that the phrase "Shushkavakrishta" (dry utterance) refers to a withered or decayed verse, as it is shown by the worn-out sloka.
english translation
atra zuSkAkSaraireva hyavakRSTA dhruvA yataH । tasmAcchuSkAvakRSTeyaM jarjarazlokadarzitA ॥ 25॥
hk transliteration by Sanscript