hi yes!
so "saint" is just the english word saint.
and "ó murċaiḋ" is more usually spelt "ó murchaidh" (since the letters with the dots haven't really been in widespread use in irish since like the 60s/70s). it comes from the first name "murchadh" (which i also use). "murchadh" is pronounced sort of like "MUR-uh-khuh", and "murchaidh" more like "MUR-uh-khee". there's sort of a syllable between the R and C that isn't written.
and the "ó" is like a long "oh" sound.
there's an audio pronounciation of "murchadh" here that i found, although they've used the spelling "murchadha".
anyway, i hope that was useful!!