semimean adjective 2noun 1forms 1 adjective2 •Pertaining to half the length of the middle axis on an ellipse (halfway between the major and minor axes).The planes in which lie the semimajor and semimean axes of both the pebbles and quartz-feldspar aggregates coincide with those of the crystalline schistosity (Sj, which follows the bedding (S0). — 1970 •Somewhat or partially mean. noun1 •The result obtained by taking either the largest or smallest half of the values and calculating the mean.Moreover, semimeans unify many of the more common measures. — 1983 formssemimeans
