Is it ensure, insure, or assure?
1570s, common name of Dianthus, a garden plant of various colors, of unknown origin. Its use for "pale rose color" first recorded 1733 (pink-coloured is recorded from 1680s), from one of the colors of the flowers. The plant name is perhaps from pink (v.) via notion of "perforated" petals, or from Dutch pink "small" (see pinkie), from the term pinck oogen "half-closed eyes," literally "small eyes," which was borrowed into English (1570s) and may have been used as a name for Dianthus, which sometimes has pale red flowers.
The flower meaning led (by 1590s) to a figurative use for "the flower" or finest example of anything (e.g. Mercutio's "Nay, I am the very pinck of curtesie," Rom. & Jul. II.iv.61). Political noun sense "person perceived as left of center but not entirely radical (i.e. red)" is attested by 1927, but the image dates to at least 1837. Pink slip "discharge notice" is first recorded 1915. To see pink elephants "hallucinate from alcoholism" first recorded 1913 in Jack London's "John Barleycorn."
c.1200, pungde "pierce, stab," later (early 14c.) "make holes in; spur a horse," of uncertain origin; perhaps from a Romanic stem that also yielded French piquer, Spanish picar (see pike (n.2)). Or perhaps from Old English pyngan and directly from Latin pungere "to prick, pierce" (see pungent). Surviving mainly in pinking shears.
An operative or agent of the Pinkerton detective agency: how you suppose Pinkies get trainin' (1850+)
any of several flowering plants of the genus Dianthus in the pink family (Caryophyllaceae), grown widely in garden borders. The approximately 300 species in the genus are nearly all natives of the Eastern Hemisphere and are found chiefly in the Mediterranean region. They are mostly short herbaceous perennials, many of which are tufted or mat-forming hardy evergreens, often with very showy flowers. There are also some annual forms. Especially noteworthy are the fragrant-flowered grass, or cottage, pink (D. plumarius); maiden, or meadow, pink (D. deltoides); and rainbow, or China, pink (D. chinensis). Most pinks are suited to rock gardens. The small but showy and often fragrant flowers are mostly pink to deep rose, some being red, purple, white, or yellow. Pinks are widely grown in American and European gardens, being of relatively easy culture. Both annual and perennial Dianthus species may be grown from seed sown in the spring in ordinary moist garden soil in a sunny location. The perennials will bloom the following summer and may be increased by cuttings or division of clumps.