- Physics. involving a change in quantum numbers, permitted by the selection rules: allowed transition.
Origin of allowed
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for unallowed
These unallowed practices are, at the same place, contrasted with true leechcraft, the skill of a doctor: comp.
He would needs, by his usual power, have a thing allowed him which by the laws was unallowed.The Confessions of Saint Augustine
And love unsanctioned, unallowed—perhaps forbidden, by some one who has ascendancy over her.The Death Shot
Word Origin and History for unallowed
late 14c., "praised;" mid-15c., "assigned as a due share;" late 15c., "permitted," past participle adjective from allow.
Online Etymology Dictionary, © 2010 Douglas Harper