At some point in the past I encountered the following verbal analogy:
SWEET NESS : SUFFIX :: BOAT SWAIN : ?
In my view, the question is asking what one would term the "swain" morpheme in "boatswain".
I have ruled out suffix itself as "swain" is neither an inflectional nor (appears to be) a derivational ending.
Some answers I have found and excluded are:
- suprafix/superfix : this pertains to the patterns of tone or stress on various parts of a word that may determine its meaning, e.g. to distinguish between the verb form of conduct from the noun form
- stem : would only work if you considered "boat" as a prefix
My best guess so far would be "root", in that the word "boatswain" consists of two roots -- "boat" and "swain" -- in a similar way to the word "wheelchair".
What do the expert linguists among you think?