'rarely-checked' originates from the combination of 'rarely,' meaning 'not often,' and 'checked,' the past participle of 'check,' meaning 'to examine or verify.'

'Rarely' comes from Middle English 'rarelī,' and 'check' comes from Old French 'eschequier,' which evolved into the modern English 'check.'

Initially, 'rarely' meant 'seldom' and 'check' meant 'to inspect,' and these meanings have largely remained the same in modern usage.