1. The nail of the thumb. Often in allusive expressions; with quot. 1604 cf. SUPERNACULUM.
1604. Dekker, 1st Pt. Honest Wh., I. v. Cast. Pledge him…. Flu. So: I ha done you right on my thumb naile.
1648. Herrick, Hesper., To his Booke (1869), 228. Be bold, my booke, nor be abasht, or feare The cutting thumb-naile, or the brow severe.
1727. Somerville, Sweet-scented Miser, 27. On his thumb-nail it might be wrote ‘A penny sav’d’s a penny got.’
1841–4. Emerson, Ess., Nat., Wks. (Bohn), I. 228. The whole code … may be written on the thumbnail.
2. transf. A drawing or sketch of the size of the thumb-nail; hence fig. a brief word-picture. Chiefly attrib., as thumb-nail sketch.
1852. Spirit of the Age, 31 March, 3/2. I now indite this ‘thumb nail sketch,’ to show what may be accomplished by perseverance and patience.
1900. D. Woodside, Life H. Calderwood, ix. 208. Small ink-sketches of the thumb-nail order.
1901. Daily Chron., 3 Jan., 4 (Cass. Suppl.). The truth of Dickens’s vignettes and thumb-nails of humanity.
1909. Westm. Gaz., 4 Jan., 1/3. There are also ‘thumb-nails’ of some French figures, and … little pencil portraits of well-known faces.
