Just for interest, is this word used for both tobacco products and fot food items? or would, for instance 'smoked salmon' use a different word?
Haha no, good question. You'd only smygu (or smocio) for tobacco.
The verbnoun for "smoke" fish is actually cochi "redden": cochi eog/samwn "smoke salmon".
But if you're using it as an adjective "smoked" then you're more likely to see the noun mwg "smoke" used as an attributive: eog/samwn mwg "smoked salmon" and likewise bacwn/caws mwg "smoked bacon/cheese". Blasus!