nonglutinous grain
粫 refers to nonglutinous grain, specifically rice that is not sticky. It is a specialized term for a type of grain texture.
粫 combines 米 (rice) with 而, which likely contributes the sound. The character was created to specifically denote nonglutinous rice.
Rice 米 that needs 而 a special name because it isn't sticky: 粫 is nonglutinous grain.
For ジ, imagine a giant grain of nonglutinous rice with the letter 'G' on it: G -> ジ, and it's not sticky at all.