'unexpectedly-led' originates from the combination of 'unexpectedly' and 'led', where 'unexpectedly' is derived from 'unexpected', meaning 'not anticipated', and 'led' is the past participle of 'lead', meaning 'to guide or direct'.

'unexpectedly' changed from the Old English word 'unæwæcned', and 'led' from the Old English 'lædan', eventually forming the modern English phrase 'unexpectedly-led'.

Initially, 'unexpectedly' meant 'not foreseen', and 'led' meant 'guided', and this meaning has largely remained the same in modern usage.