whilst

Drivers must switch off engines whilst on stand. ― instruction on a bus stand sign

[P]ray, step down to the cellar and fetch us a bottle of the Burgundy, 1678—it is the fourth bin from the right-hand turn—And I say, Craigie—you may fetch up half-a-dozen whilst you are about it—Egad, we'll make a night on't.

His company must do his minions grace, / Whil'ſt I at home ſtarue for a merrie looke: / Hath homelie age th'alluring beauty tooke / From my poore cheeke?

Modern engine sheds of advanced design have also been built at Radyr, Abercynon, and elsewhere, whilst other depots have been remodelled and re-equipped.