the GNU version of the Collaborative International Dictionary of English
adj. Of or pertaining to actinism.
The Century Dictionary and Cyclopedia
Pertaining to actinism; having the property of actinism.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. relating to or exhibiting actinism
Word Usage
"Thus from the work of Hertz and his successors we know that light, and more particularly what we call actinic light, is an effective means of setting free electrons from certain substances."