midmost

From Old English medemest, superlative of medeme (“middling”), from Proto-Germanic *medumô. Reanalyzed as mid +‎ -most.

midmost (not comparable)

1. In the exact middle, or nearest to the exact middle; middlemost
   • 1908, Kenneth Grahame, The Wind in the Willows

     A wide half-circle of foam and glinting lights and shining shoulders of green water, the great weir closed the backwater from bank to bank, troubled all the quiet surface with twirling eddies and floating foam-streaks, and deadened all other sounds with its solemn and soothing rumble. In midmost of the stream, embraced in the weir's shimmering arm-spread, a small island lay anchored, fringed close with willow and silver birch and alder.