While, conj.
 1. During the time that; as long as; whilst; at the same time that; as, while I write, you sleep.  “While I have time and space.”
    Use your memory; you will sensibly experience a gradual improvement, while you take care not to overload it.   --I. Watts.
 2. Hence, under which circumstances; in which case; though; whereas.
 While as, While that, during or at the time that. [Obs.]