level

• n. 水平; 標準; 水平面
• adj.水平な; 平らな; 同じ高さの
• vi. 水平を目指す；水平にする；水平にする
• vt. 平らにする；揃える；平らにする
• n. （水平な）人名；（仏語）ルヴェイユ

語源はラテン語のlibella（天秤、天秤）から。

level

level: [14] The Latin word for a ‘balance’ or ‘scales’ was libra (it has given English Libra the zodiacal sign [14] and also lies behind many terms for units of measurement, including litre and the abbreviation lb for ‘pound’). Its diminutive form was lībella, which denoted an ‘instrument for checking horizontality’, and hence a ‘horizontal line’. It passed into Old French as livel (which in modern French has become niveau ‘level’), and English took it over as level.
=> litre

level (n.)

mid-14c., "tool to indicate a horizontal line," from Old French livel "a level" (13c.), ultimately from Latin libella "a balance, level," diminutive of libra "balance, scale, unit of weight," from PIE *lithra. Cognate Spanish nivel, Modern French niveau are from the same source but altered by dissimilation. Meaning "horizontality" is from c. 1400. Meaning "position as marked by a horizontal line" is from 1530s. Phrase on the level "fair, honest" is from 1872; earlier it meant "moderate, without great ambition" (1790).

level (v.)

mid-15c., "to make level," from level (n.). From c. 1600 as "to bring to a level;" 1958 as "to cease increasing." Meaning "to aim a gun" is late 15c. Slang sense of "tell the truth" is from 1920. To level up "to rise" is attested by 1863.

A word here as to the misconception labored under by our English neighbor; he evidently does not understand the American manner of doing things. We never level down in this country; we are always at work on the up grade. "Level up! Level up!" is the motto of the American people. [James E. Garretson, "Professional Education," in "The Dental Cosmos," Philadelphia, 1865]

To level off "cease rising or falling" is from 1920, originally in aviation.

level (adj.)

early 15c., from level (n.). To do one's level best is from 1851.

1. Solid low- level waste will be disposed of deep underground.

放射性レベルの低い固体廃棄物は地下深く埋設処理される。

2.Faculty members complain that thair students are unprepared to do college- level work.

カレッジの先生たちは、学生がまだ大学の授業に慣れていないと愚痴をこぼしている。

3.The water level in Lake Taihu has reached record levels.

太湖水位が過去最高値に達した。

4.The person who embodies democracy at the local level is the mayor.

地方で民主を代表する人は市長である。

5.The results show the level of frustration among hospital doctors.

これらの結果は、病院の医師の不満の程度を示している。