Ground level.

(Internet slang) An interest or specialized knowledge in an subject seen as uncool, especially related to video games and otaku culture.

(aviation) The lowest flight level above the transition altitude; depends on the transition altitude and the measured or calculated sea-level atmospheric pressure. The flight level at which a descending aircraft's barometric altimeters are reset from a constant setting of 1013.25 hectopascals to the setting corresponding to the actual measured or calculated atmospheric pressure at mean sea level.

A level at the height of one's eyes.

simple past tense and past participle of level off

present participle of level off

simple past tense and past participle of level off

(often attributive) The level of the ground, the surface of the earth. / Ground floor (of a building) / (physics) Ground state, the stationary state of lowest energy of a particle.

Lowest, basic, unsophisticated level.

(idiomatic) The lowest, basic, least sophisticated level.