a. and sb. [f. Gr. ἀντί against + κλίν-ειν to lean, slope + -AL. Cf. Gr. ἀντικλίν-ειν to lean against (each other).] A. adj.
1. Geol. Forming a ridge, in which strata lean against each other, and whence they slope down, or dip, in opposite directions. The opposite of synclinal.
1833. Lyell, Princ. Geol., III. 287. The Hastings sands, forming an anticlinal axis, on each side of which the other formations are arranged with an opposite dip.
1848. Miller, First Impress., viii. (1857), 134. The strata shelve downwards on both sides from the anticlinal line a-top.
2. Anat. (A vertebra) having an upright spine, towards which the spines on both sides incline.
1870. Rolleston, Anim. Life, 12. The tenth [dorsal vertebra of the Rabbit] is the anticlinal vertebra.
B. sb. Geol. [by ellipsis]. An anticlinal fold, axis, crest or line; a line whence strata dip in opposite directions.
1849. Murchison, Siluria, v. 100. The same North and South anticlinal which is apparent in May Hill and Huntley Hill.
1869. Phillips, Vesuv., ix. 255. Anticlinals and synclinals, in the earth’s crust.
