'equal-ranked' is a compound formed from 'equal' and the past-participle adjective 'ranked'. 'equal' originates from Latin, specifically the word 'aequalis', where 'aequus' meant 'even' or 'level'. 'rank' (in ranked) originates from Old French 'renc'/'rang', ultimately from a Germanic source meaning 'row' or 'line'.

'equal' came into English via Old French and Middle English from Latin 'aequalis' and became the modern English word 'equal'; 'rank' entered English from Old French 'rang' (from a Germanic root meaning 'row'), later used as a verb 'to rank' and then as the past participle 'ranked'. The compound 'equal-ranked' is a modern English formation combining these elements.

Initially, 'aequalis' signified 'even' or 'level' and 'rank' signified 'row' or 'position'; over time these developed into 'equal' (having the same measure) and 'rank' (position or status). Combined, 'equal-ranked' now means 'having the same rank or status.'