I. ˈmēnˌ(h)wīl noun
Etymology: Middle English mene while, from mene occupying a middle position + while
: meantime
were being developed in the meanwhile by engineers — S.I.Hayakawa
II. adverb
Etymology: Middle English menewhile, from mene while, n.
1. : during the intervening time : for the time being
children who are crippled … meanwhile are cut off from ordinary opportunities — Martha M. Eliot
2. : at the same time
meanwhile he was becoming more and more engaged in … the main activity of his life — W.S.Grant