adj. 1. Sticking together; cohering.
2. a. Marked by an orderly, logical, and aesthetically consistent relation of parts: a coherent essay.
b. Able to express one's thoughts in a clear and orderly manner: a first responder who remained coherent during the crisis.
3. Physics Of, relating to, or having waves with similar direction, amplitude, and phase that are capable of exhibiting interference.
4. Of or relating to a system of units of measurement in which a small number of basic units are defined from which all others in the system are derived by multiplication or division only.
5. Botany Sticking to but not fused with a part or an organ of the same kind.