Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. sprētus, a, um, Part. of sperno.
2. sprētus, ūs, m. [sperno], a despising, disdain, scorn, contempt (post-class. and very rare): insolentissimo spretu deos neglegit, App. de Deo Socr. p. 43, 3: spretui maximc est judiciis, Sid. Ep. 3, 14 fin.