Thanks. In many way the ideal gloss for this sort of term is brief and accurate and gives a starting point for further exploration.

I believe this version is fine, I couldn't really come up with something better. I agree that it's far too obscure, and most likely complex, to attempt explaining it. I doubt that there's going to be many people looking here first when encountering this term but I think it at least gives them something to go off of if they do. I think Imabi has a somewhat comprehensive article about this IIRC.

If noone else has anything to add then this and the other one can probably be closed.

Reopen

I think the glossing needs to be much simpler without attempting to explain such an obscure term. I think "covered" is a better match for 被覆.
I'll approve this version and reopen for further discussion.

@@ -16,2 +16,2 @@
-<gloss>covert form of native Japanese a word (used only in compounds; e.g. かな instead of かね in 金槌)</gloss>
-<gloss>bound form</gloss>
+<gloss>bound form (in Japanese morphology)</gloss>
+<gloss>covered form</gloss>

Important to note

@@ -15 +15 @@
-<gloss>covert form of a word (used only in compounds; e.g. かな instead of かね in 金槌)</gloss>
+<gloss>covert form of native Japanese a word (used only in compounds; e.g. かな instead of かね in 金槌)</gloss>