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.
The definition of flexible is someone or something that bends easily, is easily persuaded or can be changed easily. 1  An example of flexible is a yoga expert. 2  An example of flexible is a work schedule that allows work to be done at any time during the day.