D defs.my
Entry 1 sense Webster, 1913

Horizontally

· Hor·i·zon·tal·ly · IPA /hˌɔrɪzˈɑntəliː/
01 adv. In a horizontal direction or position; on a level; as, moving horizontally.
  1. 1.
    In a horizontal direction or position; on a level; as, moving horizontally.