carbonium ion
(redirected from Methonium)Also found in: Dictionary.
carbonium ion
[kär′bōn·ē·əm ‚ī·ən] (organic chemistry)
A carbocation which has a positively charged carbon with a coordination number greater than 3.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.