Concurrent

1. n. One of the supernumerary days of the year over fifty-two complete weeks; — so called because they concur with the solar cycle, the course of which they follow.
2. a. Acting in conjunction; agreeing in the same act or opinion; contributing to the same event or effect; cooperating.
3. a. Conjoined; associate; concomitant; existing or happening at the same time.
4. a. Joint and equal in authority; taking cognizance of similar questions; operating on the same objects; as, the concurrent jurisdiction of courts.
5. a. Meeting in one point.
6. n. One who, or that which, concurs; a joint or contributory cause.
7. n. One pursuing the same course, or seeking the same objects; hence, a rival; an opponent.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.