'rarely-approved' is a compound word formed from 'rarely' and 'approved'. 'Rarely' originates from Middle English 'rarelī', meaning 'seldom', and 'approved' comes from Old French 'aprover', meaning 'to prove or demonstrate'.

'Rarely' evolved from Middle English 'rarelī', while 'approved' transformed from Old French 'aprover' to the modern English 'approve'.

Initially, 'rarely' meant 'seldom' and 'approved' meant 'to prove or demonstrate'. The compound 'rarely-approved' retains the meaning of 'not often given approval'.