mean sea level
71Zero-level elevation — Zero elevation surface is a widely accepted vertical reference point that is used to describe a surface, such as that of a planet. The value of this datum is usually adopted by statute. This elevation is used, for example, to build a texture map… …
72a spirit level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
73Air level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
74Box level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
75Carpenter's level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
76Mason's level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
77Plumb level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
78Spirit level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
79Surveyor's level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …
80Water level — Level Lev el (l[e^]v [e^]l), n. [OE. level, livel, OF. livel, F. niveau, fr. L. libella level, water level, a plumb level, dim. of libra pound, measure for liquids, balance, water poise, level. Cf. {Librate}, {Libella}.] 1. A line or surface to… …