'rarely-applied' originates from the combination of 'rarely,' meaning 'not often,' and 'applied,' the past participle of 'apply,' meaning 'to put into use.'

'Rarely-applied' combines the adverb 'rarely' with the past participle 'applied' to form an adjective describing something not often used.

Initially, 'rarely' meant 'seldom' and 'applied' meant 'put into use.' Together, they describe something not often put into use.