'properly-left' is a compound word formed from 'properly' and 'left', where 'properly' originates from Latin 'proprius', meaning 'one's own', and 'left' from Old English 'lyft', meaning 'weak'.

'properly' evolved from Middle English 'properly', and 'left' from Old English 'lyft', eventually forming the modern English compound 'properly-left'.

Initially, 'properly' meant 'in a proper manner', and 'left' referred to the direction, maintaining its meaning in the compound form.