Freebase(0.00 / 0 votes)Rate this definition: Diltiazem. Diltiazem is a nondihydropyridine member of the class of drugs known as calcium channel blockers, used in the treatment of hypertension, angina pectoris, and some types of arrhythmia. It is also an effective preventive medication for migraine. It is a class 3 antianginal drug, and a class IV antiarrhythmic.
Rigid definition, stiff or unyielding; not pliant or flexible; hard: a rigid strip of metal. See more.
Definition of solid. 1  a three-dimensional shape. 2  the state in which a substance has no tendency to flow under moderate stress; resists forces (such as compression) that tend to deform it; and retains a definite size and shape.  a substance that is solid at room temperature and pressure.