Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* spectus, ūs, m. [specio], look, appearance, aspect: spectu sine praepositione Pacuvius in Duloreste usus est, cum ait: spectu protervo ferox, Fest. s. h. v. p. 330 Müll.; Pac. Fragm. Trag. v. 147 Rib.