n. [ Gr. ge`a, gh^, the earth + E. synclinal. ] (Geol.) the downward bend or subsidence of the earth's crust, which allows of the gradual accumulation of sediment, and hence forms the first step in the making of a mountain range; -- opposed to geanticlinal. [ 1913 Webster ]

a. [ Gr. &unr_; to incline together; sy`n with + &unr_; to incline. ] 1. Inclined downward from opposite directions, so as to meet in a common point or line. [ 1913 Webster ]

2. (Geol.) Formed by strata dipping toward a common line or plane; as, a synclinal trough or valley; a synclinal fold; -- opposed to anticlinal. [ 1913 Webster ]

☞ A downward flexure in the case of folded rocks makes a synclinal axis, and the alternating upward flexure an anticlinal axis. [ 1913 Webster ]

n. (Geol.) A synclinal fold. [ 1913 Webster ]