crystallinChem.|ˈkrɪstəlɪn| [f. as prec. + -in.] An albuminoid substance contained in the crystalline lens of the eye. 1847–9Todd Cycl.Anat. IV. 169/1 There is another modification of protein..called both globulin and crystallin.1863–72Watts Dict.Chem.Crystallin or globulin.