Definitions
1.AdverbOften preceded by the: During the time; meanwhile.
2.ConjunctionSynonym of while."Drivers must switch off engines whilst on stand."
3.ConjunctionDuring the whole, or until the end, of the time that; as long as, at the same time."Drivers must switch off engines whilst on stand."
4.ConjunctionWithin, or before the end, of the time that.
5.ConjunctionAlthough; in contrast; whereas.
6.ConjunctionBesides; in addition.
7.ConjunctionOnly if; provided that; as long as; so long as.