Rigid

Rig"id (?), a. [L. rigidus, fr. rigere to be stiff or numb: cf. F. rigide. Cf. Rigor. ] 1. Firm; stiff; unyielding; not pliant; not flexible.

Upright beams innumerable
Of rigid spears.
Milton.

2. Hence, not lax or indulgent; severe; inflexible; strict; as, a rigid father or master; rigid discipline; rigid criticism; a rigid sentence.

The more rigid order of principles in religion and government.
Hawthorne.

Syn. -- Stiff; unpliant; inflexible; unyielding; strict; exact; severe; austere; stern; rigorous; unmitigated.