| Noun | 1. | muscle contraction - (physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber) shortening - act of decreasing in length; "the dress needs shortening" contracture - an abnormal and usually permanent contraction of a muscle tetanus - a sustained muscular contraction resulting from a rapid series of nerve impulses uterine contraction - a rhythmic tightening in labor of the upper uterine musculature that contracts the size of the uterus and pushes the fetus toward the birth canal Braxton-Hicks contraction, false labor - painless contractions of the muscles of the uterus that continue throughout pregnancy with increasing frequency physiology - the branch of the biological sciences dealing with the functioning of organisms |