Without preparation or forethought; extemporaneously.(adverb)
Performed or expressed without preparation or forethought. See Synonyms at extemporaneous.(adjective)
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 "offhand" in a sentence
"Can’t think of the title offhand, but it’s definitely on my list."
"The only answer I can think of offhand is the bond market & those who have an interest in fixed incomes since inflation would be painful for both."
"The only answer I can think of offhand is the bond market"