atone: [16] As its spelling suggests, but its pronunciation disguises, atone comes from the phrase at one ‘united, in harmony’, lexicalized as atone in early modern English. It may have been modelled on Latin adūnāre ‘unite’, which was similarly compounded from ad ‘to, at’ and ūnum ‘one’. => at, one[atone etymology, atone origin, 英语词源]