  We study spectral and temporal properties of Galactic short orbital period
transient black hole XTE J1118+480 during its 2005 outburst using archival data
of RXTE PCA and HEXTE instruments in the combined energy range of $3-100$ keV.
Spectral analysis with the physical two-component advective flow (TCAF) model
allows us to understand the accretion flow properties of the source. We found
that this outburst of XTE J1118+480 is an unconventional outburst as the source
was only in the hard state (HS). Our spectral analysis suggests that during the
entire outburst, the source was highly dominated by the low angular momentum
sub-Keplerian halo rate. Since the source was active in radio throughout the
outburst, we make an effort to estimate X-ray contribution of jets in total
observed X-ray emissions from the spectral analysis with the TCAF model. The
total X-ray intensity shows a similar nature of evolution as of radio and jet
X-ray fluxes. This allowed us to define this `outburst' also as a jet dominated
`outburst'. Total X-ray flux also found to subside when jet activity
disappears. Our detailed spectral analysis also showed that although the source
was only in the HS during the outburst, in the late declining phase spectrum
became slightly softer due to the slow rise in the Keplerian disk rate.
