  We present a detailed radio, X-ray and optical study of a newly discovered
Large Magellanic Cloud (LMC) supernova remnant (SNR) which we denote MCSNR
J0508-6902. Observations from the Australian Telescope Compact Array (ATCA) and
the $\textit{XMM-Newton}$ X-ray observatory are complemented by deep H$\alpha$
images and Anglo Australian Telescope AAOmega spectroscopic data to study the
SNR shell and its shock-ionisation. Archival data at other wavelengths are also
examined. The remnant follows a filled-in shell type morphology in the
radio-continuum and has a size of $\sim$74 pc $\times$ 57 pc at the LMC
distance. The X-ray emission exhibits a faint soft shell morphology with
Fe-rich gas in its interior $-$ indicative of a Type Ia origin. The remnant
appears to be mostly dissipated at higher radio-continuum frequencies leaving
only the south-eastern limb fully detectable while in the optical it is the
western side of the SNR shell that is clearly detected. The best-fit
temperature to the shell X-ray emission ($kT = 0.41^{+0.05}_{-0.06}$ keV) is
consistent with other large LMC SNRs. We determined an O/Fe ratio of $<21$ and
an Fe mass of 0.5-1.8$~M_{\odot}$ in the interior of the remnant, both of which
are consistent with the Type Ia scenario. We find an equipartition magnetic
field for the remnant of $\sim$28 $\mu$G, a value typical of older SNRs and
consistent with other analyses which also infer an older remnant.
