Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. stellĭo (stēlĭo), ōnis, m. [stella].
2. Stellio, ōnis, m. [1. stellio], a Roman surname, e. g. C. Afranius Stellio, Liv. 39, 23, 2.