horizontally

from WordNet (r) 3.0 (2006)

horizontally
    adv 1: in a horizontal direction; "a gallery quite often is
           added to make use of space vertically as well as
           horizontally"

from The Collaborative International Dictionary of English v.0.48

Horizontally \Hor`i*zon"tal*ly\, adv.
   In a horizontal direction or position; on a level; as, moving
   horizontally.
   [1913 Webster]

[email protected]