Late 16th century: from Old French aloi (noun) and French aloyer (verb), both from Old French aloier, aleier 'combine', from Latin alligare 'bind'. In early use the term denoted the comparative purity of gold or silver; the sense 'mixture of metals' arose in the mid 17th century.

• ally from Middle English:

  Latin alligere ‘combine together’, formed from ad- ‘to(gether)’ and ligare ‘bind’ developed into two closely related words in Old French: alier which became ally in English, and aloyer which became alloy (late 16th century). Ligare is also hidden in furl (late 16th century) which comes from French ferler, from ferm ‘firm’ and lier ‘bind’; league (Late Middle English) a binding together; and oblige (Middle English) originally meaning ‘bind by oath’.