Word Study
spirit level
ROGET THESAURUS
spirit level
Horizontality
N horizontality, flatness, level, plane, stratum, dead level, dead flat, level plane, recumbency, lying down, reclination, decumbence, decumbency, discumbency, proneness, accubation, supination, resupination, prostration, azimuth, plain, floor, platform, bowling green, cricket ground, croquet ground, croquet lawn, billiard table, terrace, estrade, esplanade, parterre, table land, plateau, ledge, butte, mesa (plain), level, spirit level, horizontal, level, even, plane, flat, flat as a billiard table, flat as a bowling green, alluvial, calm, calm as a mill pond, smooth, smooth as glass, recumbent, decumbent, procumbent, accumbent, lying, prone, supine, couchant, jacent, prostrate, recubant, horizontally, on one's back, on all fours, on its beam ends.For further exploring for "spirit level" in Webster Dictionary Online