Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
suppĕtĭor (subp-), ātus, 1, v. dep. n. [suppetiae], to come to the aid of, to assist, succor (very rare; most freq. in App.): quod mihi suppetiatus es, gratissimum est, Cic. Att. 14, 18, 2: miserrimo seni, App. M. 8, p. 210, 32.
Absol.: suppetiatum decurrunt anxii, run to aid, App. M. 4, p. 147, 9: proclamare suppetiatum, id. ib. 1, p. 108, 30; 8, p. 209, 35.