'unexpectedly-increased' is a compound word formed from 'unexpectedly' and 'increased'. 'Unexpectedly' originates from the Latin word 'exspectare', meaning 'to look out for', with the prefix 'un-' indicating negation. 'Increased' comes from the Latin 'increscere', where 'in-' meant 'into' and 'crescere' meant 'to grow'.

'Unexpectedly' evolved from the Old French 'especier', while 'increased' transitioned from the Old French 'encreistre'.

Initially, 'unexpectedly' meant 'not looked for', and 'increased' meant 'grown'. The compound form retains these meanings, indicating growth that was not anticipated.