Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* callisco, ĕre, v. inch. [calleo], to become dull, insensible: aures nobis calliscerunt ad injurias, Cato ap. Non. p. 89, 27 sq. (Meyer, calliscunt, Or. Rom. Fragm. p. 118).