A stone that is placed upon or forms the top of something; a cap-stone: chiefly fig. Also, the upper end-stone or jewel in a chronometer.
1658–9. in Burton’s Diary (1828), III. 222. Our kings: those that know history, know they were kings before the Parliament declared them so, their top-stone.
1662. Jer. Taylor, Serm. to Univ. Dublin, 51. Humane learning is an excellent Foundation; but the top-stone is laid by Love and Conformity to the will of God.
1707. Mortimer, Husb. (1721), I. 3. Where are abundance of flat Stones, they make Fences of them by laying of them one upon another like a Wall, and only lay the Top-stones in Clay to keep them together, the weight of which secures the under ones.
1871. Routledge’s Ev. Boy’s Ann., Sept., 513. Religion, that indispensable top-stone of every social edifice.
1901. N. Amer. Rev., Feb., 292. The strict observance of the rules of Caste, with the Brâhman as the top-stone of the social pyramid, was everything.
