tanutta : [nt.] thinness; diminution; reduction.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Tanutta (nt.) [n. -- abstr. of tanu] diminution, reduction, vanishing, gradual disappearance A i.160 (manussānaŋ khayo hoti tanuttaŋ paññāyati); ii.144 (rāga˚, dosa˚, moha˚); esp. in phrase (characterizing a sakadāgāmin) "rāga -- d. -- mohānaŋ tanuttā sakadāgāmī hoti" D i.156; S v.357 sq., 376, 406; A ii.238; Pug 16.

Pali-English Dictionary, TW Rhys Davids, William Stede,