Horizontal means "flat" or "having no slope" or "with a slope of zero" or the like. It's just what you think it is. It has "across" to it, but no "up" or "down" aspect. A horizontal line is one that follows the horizon, or is "straight across" from one side to the other. The "no slope" or "zero slope" speaks to the mathematical definition.
For kids: it is not up and down, it is side to side.So it is going across or sideways.
Horizontally
horizontally
The bookshelf is positioned horizontally against the wall.
Cells that run horizontally
Stems which grow horizontally are called stolons. Stems which grow horizontally are called stolons.
Horizontally
both vertically and horizontally
vertically and horizontally. Vertically, they get taller as new growth sprouts from the top every year. Horizontally, they get thicker and branches get longer.
Horizontally
left to right --------------------------------
Yes in MS office text can be typed horizontally.
No, in a worksheet rows run horizontally and columns run vertically.