  The Fermi-LAT unassociated sources represent some of the most enigmatic
gamma-ray sources in the sky. Observations with the Swift-XRT and -UVOT
telescopes have identified hundreds of likely X-ray and UV/optical counterparts
in the uncertainty ellipses of the unassociated sources. In this work we
present spectral fitting results for 205 possible X-ray/UV/optical counterparts
to 4FGL unassociated targets. Assuming that the unassociated sources contain
mostly pulsars and blazars, we develop a neural network classifier approach
that applies gamma-ray, X-ray, and UV/optical spectral parameters to yield
descriptive classification of unassociated spectra into pulsars and blazars.
From our primary sample of 174 Fermi sources with a single X-ray/UV/optical
counterpart, we present 132 P_bzr > 0.99 likely blazars and 14 P_bzr < 0.01
likely pulsars, with 28 remaining ambiguous. These subsets of the unassociated
sources suggest a systematic expansion to catalogs of gamma-ray pulsars and
blazars. Compared to previous classification approaches our neural network
classifier achieves significantly higher validation accuracy and returns more
bifurcated P_bzr values, suggesting that multiwavelength analysis is a valuable
tool for confident classification of Fermi unassociated sources.
