Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
exsŭpĕrantĭa (exup-), ae, f. [exsupero], pre-eminence, superiority (rare but class.): an hoc non ita fit omni in populo? nonne omnem exsuperantiam virtutis oderunt? * Cic. Tusc. 5, 36, 105: ingens Scipionis (with fiducia), Gell. 4, 18, 2: splendoris vel altitudinis, id. 14, 1, 12.