plane (adjective) plane: level, horizontal
Detalii: plane is essentially the same word as plain, both ultimately coming from Latin planus 'flat' or 'clear'
Sinonime: advance, approach, be dangerous, be gathering, be imminent, be in the air, be in the offing, be on the horizon,
brew, brewing, come on, forebode, foreshadow, frighten, hang over, imperil, jeopardize, loom,
lower,
menace, overhang, portend, presage, put at risk, put in jeopardy, warn
Antonime: upright, vertical