noun. a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape.
1. Noun, singular or mass Before long, spindle fibers on each side of the cell have become attached to the kinetochore on the chromatid in each pair that happens to lie on the same side of the cell. 2. Verb, past tense The microtubule spindle fibers connect to the centromeres at a location called the *kinetochore*.