INFLUENCE OF ACCENT IN COMPOUNDING
Some writers lay much stress on the influence of accent in the formation of compounds while others ignore it entirely. Accent undoubtedly has some influence and the theory may be easily and intelligibly expressed. It ought to be understood, but it will not be found an entirely safe guide. Usage has modified the results of compounding in many cases in ways which do not lend themselves to logical explanation and classification.
The general principle as stated by Mr. Teall is as follows:
When each part of the compound is accented, use the hyphen; laughter-loving.
When only one part is accented, omit the hyphen; many sided.
When the accent is changed, print the compound solid; broadsword. This follows the general rule of accenting the first syllable in English words.