To express an opinion: opined on the defendant's testimony. (verb-intransitive)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "opine" in a sentence
"Harper is probably the best leader on offer but, as comedian Dennis Miller might opine, that is like being the smartest kid in summer school."
"'opine' -- and that innumerable things were within your horizon which had no place within mine."
"(Not for the least of reasons which include being able to use a form of the word "opine".)"