synclinal

adj

1. Having or relating to a torsion angle between 30° and 90°
2. Inclined downward from opposite directions, so as to meet in a common point or line.

   “The doctor's eyebrows had gone synclinal from puzzlement without his awareness.”

3. Formed by strata dipping toward a common line or plane.

   “a synclinal trough or valley”

   “a synclinal fold”

noun

1. A synclinal fold.

   “But being chiefly sections of younger rocks than ours, the Austrian diagrams exhibit a more disturbed surface, so far as regards faults and slips, snapped anticlinals, upshoved synclinals, lapped folds, […]”