relaxation: a method of solving simultaneous equations by guessing a solution and then reducing the errors that result by successive approximations until all the errors are less than some specified amount
calculation: the procedure of calculating; determining something by mathematical or logical methods
test-tube baby: a baby conceived by fertilization that occurs outside the mother's body; the woman's ova are removed and mixed with sperm in a culture medium - if fertilization occurs the blastocyte is implanted in the woman's uterus