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.
Full Definition of PLASTIC. 1. : a plastic substance; specifically: any of numerous organic synthetic or processed materials that are mostly thermoplastic or thermosetting polymers of high molecular weight and that can be made into objects, films, or filaments.2. : credit cards used for payment âcalled also plastic money.ull Definition of PLASTIC. 1. : a plastic substance; specifically: any of numerous organic synthetic or processed materials that are mostly thermoplastic or thermosetting polymers of high molecular weight and that can be made into objects, films, or filaments. 2.