There is a traditional Finnish instrument (kannel or kantele) which tends to be called nablium in Latin. How do I form the adjective for someone bearing this instrument using -fer? There are things like ensifer and lucifer and others, but I failed to find an example derived from a noun ending in -ium.
My intuition says it should be simply nablifer, but I am far from sure that nabliifer or some other construction should be used with such words. I do not expect to see nablifer as such attested anywhere, but I am happy to reason by analogy if I can see something analogous.
I assume a similar reasoning would apply to most words ending in -ius/-ia/-ium/-eus/-ea/-eum, but the actual question at hand concerns -ium.