'rarely-endorsed' originates from the combination of 'rarely,' meaning 'not often,' and 'endorsed,' meaning 'supported or approved.'

'Rarely' comes from Middle English 'rarelī,' and 'endorsed' comes from the Old French 'endosser,' meaning 'to put on the back.'

Initially, 'rarely' meant 'seldom' and 'endorsed' meant 'to support,' and this meaning has largely remained the same in modern usage.