Solar, for instance, is less useful in the long dark night of the northern winter.Washington Post (Aug 14, 2015) sol (sun) + ar (suffix forming adjectives) As the roots and definition show, the word should be an adjective, but the example sentence uses it as a shortened form of the noun phrase solar energy..
Disproportionality is the overrepresentation of a particular race or cultural group in a program or system compared to their representation in the general population. Disproportionality affects all systems such as the educational, mental health and judicial systems creating additional costs within these areas.
Disequilibrium is the loss of balance or feeling unsteady when you walk. Causes may include: Sensory disorders  failing vision or nerve damage in the legs, like from diabetes. Joint and muscle problems  muscle weakness and joint problems such as osteoarthritis, which is wear and tear of the joints.