1) Regularly used to mean ‘until’.
1674 forced to charge four men to watch him while I could come before one of his Majesties Justices of Peace, Quarmby
1725 left his apprentice to worke two or three days whilst he came again, Kildwick
1741 broil it before the fire while it be enough, Pontefract
1774 I suppose he will expect security for the money whilst it be collected, Holmfirth
1797 leading wheat while noon when it came rain, Sessay.