- (cartography) a line on a map indicating the steepness of a slope
- (botany) A plant that turns so that it faces the sun.
- (botany) Particularly, a purple-flowered plant of the species Heliotropium arborescens.
- 1870, Benjamin Disraeli, Lothair
- :As they entered now, it seemed a blaze of roses and carnations, though one recognized in a moment the presence of the lily, the heliotrope, and the stock.
- (colour) A light purple or violet colour.
- <table><tr><td>heliotrope colour: </td><td bgcolor="
- 9B8A86" width="80"> </td></tr></table>
- The fragrance of heliotrope flowers.
- 1881, Henry James, The Portrait of a Lady
- :... he had always smelt so much more of than of gunpowder.
- (mineralogy) A bloodstone (a variety of quartz).
- (colour) Light purple or violet.
- 1904, Jerome K. Jerome, Tommy and Co.
- :Lady in a dress with a lace collar, three flounces on the skirt?
- 1917, Zane Grey, Wildfire
- :And following that was a tortuous passage through a weird region of clay dunes, blue and violet and and lavender, all worn smooth by rain and wind.
- Keeping one"s face turned toward the sun.
- 1851, Herman Melville, Moby Dick
- : while still as on the night before, slouched Ahab stood fixed within his scuttle; his hid, glance anticipatingly gone backward on its dial; sat due eastward for the earliest sun.
- The central part, usually cylindrical, of a wheel; the nave
- A point where many routes meet and traffic is distributed, dispensed or diverted
- Hongkong airport is one of the most important air traffic hubs in Asia.
- (computers) a computer networking device connecting several ethernet ports. See switch.
- (surveying) A stake with a nail in it, used to mark a temporary point.