| Main Entry: | perpendicular |
| Part of Speech: | adjective |
| Definition: | at right angles to |
Synonyms: |
erect, horizontal, on end, plumb, sheer, stand-up, standing, steep, straight, straight-up, upright, vertical |
Antonyms: |
horizontal, level |
| Main Entry: | steep |
| Part of Speech: | adjective |
| Definition: | extreme in direction, course |
Synonyms: |
abrupt, arduous, breakneck, declivitous, elevated, erect, headlong, high, hilly, lifted, lofty, perpendicular, precipitate, precipitous, prerupt, raised, sharp, sheer, straight-up |
| Notes: | a gentle slope is a glacis; a precipitous slope is a steep |
Antonyms: |
gentle, mild, moderate |
| Main Entry: | vertical |
| Part of Speech: | adjective |
| Definition: | upright |
Synonyms: |
bolt upright, cocked, erect, on end, perpendicular, plumb, sheer, steep, straight-up, up-and-down, upward |
Antonyms: |
horizontal, prone |