upmost

There were three enclosures; but the upmost one, though carefully folded, was unsealed, and engaged his attention first.

His feet dangled on a level with the top of the upmost tree.

Hence, in the present English, the different parts of the syllable most (in words like upmost) come from different quarters.

In less than half-an-hour the ruined amphitheatre was a moving mass of heads from the ground to its upmost storey.