Your question may come from the fact that the S is sometimes pronounced as SH , but this is only after slender vowels ( E and I )
therefore fós ( 'Yet' in English ) is pronounced foss
but Aris (' again ' ) is pronounced Areesh
Depending on the dialect: g'yall; g'yowl, etc.
In Irish it's "chuir tú geall ar Chiarraí"
It doesn't have a Gaelic pronunciation: it is Latin.
Fred Geall has written: 'A History of the airport social club'
shockt
brokakh
Smeenta.
With the accent marks: Írusán [eerusaun] in Irish.
moorn-yeh
on chuninn
"eye"-nih
"Archie"
The Scottish Gaelic pronunciation would be roughly drooim;The Irish "Gaelic" pronunciation would be like drim.