monoclinic

adj. having one slope, having one incline (Geology)

In crystallography, the monoclinic crystal system is one of the 7 lattice point groups. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal length, as in the orthorhombic system. They form a rectangular prism with a parallelogram as base. Hence two pairs of vectors are perpendicular, while the third pair make an angle other than 90°.
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Adjective
1. having three unequal crystal axes with one oblique intersection; "monoclinic system"
(antonym) triclinic, anorthic
(classification) crystallography

(a.)
Having one oblique intersection; -- said of that system of crystallization in which the vertical axis is inclined to one, but at right angles to the other, lateral axis. See Crystallization.
  

monoclinic