upper surface

1. 1.

   the side that is uppermost

   Broaderside

   Narrowerceiling

Questions about upper surface

What does upper surface mean?

upper surface means "the side that is uppermost".

Is upper surface a common word?

upper surface is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.