| Main Entry: | |
| 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: | upright |
| Part of Speech: | adjective |
| Definition: | straight-up |
| Synonyms: | cocked, end on, end up, erect, on end, perpendicular, plumb, raised, sheer, stand-up, standing, steep, straight, upended, upstanding, upward, vertical |
| Antonyms: | fallen, lying, prone |
| 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 |