Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* aestĭmābĭlis, e, adj. [aestimo], worthy of estimation, valuable, estimable: aestimabile esse dicitur id, quod … aliquod pondus habeat dignum aestimatione, contaque inaestimabile, quod sit superiori contrarium, Cic. Fin. 3, 6, 20.