'unevenly-spaced' originates from the combination of 'unevenly' and 'spaced', where 'un-' is a prefix meaning 'not', 'even' means 'equal or level', and 'spaced' refers to the arrangement in space.

'unevenly-spaced' evolved from the combination of 'uneven' and 'spaced', which were used separately in Middle English and later combined in modern English.

Initially, 'unevenly' meant 'not level or equal', and 'spaced' referred to the arrangement in space. The combined term 'unevenly-spaced' retains this meaning.