Plumbago

Part of speech: noun

Pronunciation: /plʌmˈbeɪɡəʊ/

Definitions

1. A bluish-gray mineral form of carbon used as a lubricant and in pencil leads, or a flowering plant with blue or white blossoms
2. a grayish-black carbon mineral employed for lubrication and pencil manufacture, or a decorative shrub bearing blue or white flowers
3. a soft crystalline substance composed of carbon serving industrial purposes like friction reduction and writing instruments, or a climbing or bushy plant with colored blooms
4. A grayish-black crystalline carbon mineral valued for lubrication and pencil manufacture, or a decorative shrub bearing clusters of blue or white flowers
5. Either a soft metallic carbon compound serving industrial purposes like greasing machinery and making writing implements, or a tropical ornamental plant recognized by its delicate colored blooms

Etymology: Plumbago is a Latin word meaning "lead ore," built from "plumbum," the Latin for lead. The Romans applied it to a dark, lead-like mineral, and the same name was later attached to a different substance altogether. Graphite, the soft, greasy carbon mineral used in pencils, was once confused with lead ore because both are dark, heavy-looking and leave marks on the hand, which is how a word for lead came to name it. English took the Latin term directly, so the word keeps its original Latin shape and meaning in its borrowed form. The Latin root "plumbum" also gave English the adjective "plumbic" and the chemical symbol Pb, which both trace back to the same metal.

Synonyms: leadwort, graphite, pencil plant, plumbago auriculata, plumbago zeylanica