The quality of being parallel to the horizon.

Roget 213: horizontality^†; flatness; level, plane; stratum etc. 204; dead level, dead flat; level plane.    recumbency, lying down etc. v.; reclination^†, decumbence^†; decumbency^†, discumbency^†; proneness etc. adj.; accubation^†, supination^†, resupination^†, prostration; azimuth.    plain, floor, platform, bowling green; cricket ground; croquet ground, croquet lawn; billiard table; terrace, estrade^†, esplanade, parterre.    [flat land area] table land, plateau, ledge; butte; mesa (plain) 344.    [instrument to measure horizontality] level, spirit level.    ... show more