¦ noun (plural unities)
1. the state of being united.
a thing forming a complex whole.
2. Mathematics the number one.
3. a dramatic principle requiring limitation of the supposed time of a drama to that occupied in acting it or to a single day (unity of time), use of one scene throughout (unity of place), or concentration on a single plot (unity of action).
Origin
ME: from OFr. unite, from L. unitas, from unus 'one'.