thionic adjective. [Ɵʌɪ'ɒnɪk] L19.
[formed as THIO- + -IC (with -n- inserted or retained from Greek theion).]
Chemistry. thionic acid, any of a series of acids including dithionic acid and related acids represented by the formula HSO₃(S)_nHSO₃. Freq. with prefix indicating total number of sulphur atoms, as trithionic, tetrathionic, etc.

■ thionate noun (Chemistry) a salt or ester of a thionic acid L19.

[TahlilGaran] English Dictionary ▲