Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
inventum, i, n. [invenio], a device, contrivance, invention (class.): ut te omnes di cum istoc invento atque incepto perduint, Ter. Heaut. 4, 6, 7: inventa Zenonis, Cic. Mur. 29, 61: inventum medicina meum est, Ov. M. 1, 521: artium, litterarum, etc., Quint. 3, 7, 8: optima inventa, id. 5, 12, 19.