Etymology

From and- ‎(“against, back”) +‎ hātan ‎(“to command, promise”), or possibly formed in Proto-Germanic *andi- + *haitaną, of the selfsame elements. Compare Old Saxon andhētan, anthētan ‎(“to teach, vow, promise”), Old High German antheizan ‎(“to declare, pledge, promise”). More at and-, hātan.