1. Going well together; possessing harmonizing qualities.
2. Provided with a worthy adversary or competitor.
ETYM Old Eng. twin double, as. getwinne two and two, pl., twins; akin to Dutch tweeling a twin, German zwilling, Old High Germ. zwiniling, Icel. tvennr, tvinnr, two and two, twin, and to as. twi- two. Related to Twice, Two.
1. Being one of two born at a birth.
2. Being one of a pair much resembling one another.
3. Double; consisting of two similar and corresponding parts.