Sentence:  The great majority of present-day linguists fall into one or more of a number of overlapping types : those who are convinced that tone cannot be analysed , those who are personally scared of tone and tone languages generally , those who are convinced that tone is merely an unnecessary marginal <WSD>feature</WSD> in those languages where it occurs , those who have no idea how to proceed with tone analysis , those who take a simplistic view of the whole matter . 
Meaning of the word marked with <WSD> tags:  a prominent attribute or aspect of something