1012: disheveled Sep 16, 2017

Generally, affixes do not change the sound of the words to which they are bound, though sometimes the affixes will change in order to be easier to pronounce, such as 'in-' becoming 'im-' in 'impossible'. Therefore, words that take the prefix 'dis-' do not change, as is the case with 'dishonest' from 'honest' being pronounced with an /s/, even though normally in English orthography, 'sh' represents the sound /ʃ/ as in 'shoe'. Nevertheless, 'disheveled', which does have the historical 'dis-' prefix', has the '-sh-' pronounced as /ʃ/. This is because, not only is there not a Modern English word 'heveled', but also the word from which 'disheveled' originates was already pronounced with the /ʃ/: the Old French 'chevel' meaning 'hair'.  Initially, the sense that the word carried was 'having loose or uncovered hair', but because of what people associated with that idea, it eventually came to mean 'disorderly' or 'messy'.