Having one or more projecting sharp points.(adjective)
Grouchy or cross in temperament.(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 "spiky" in a sentence
"Note teasing of bangs at crown: lower part of the bang is brushed down across forehead; upper part is brushed upward in spiky faux pompadour."
"“A surface coated in spiky polymer molecules destroys the flu virus at a touch,” Scientific American reported last month."
"The problem with renewables is that most renewable types of generation are "spiky" - they are intermittent; they come at night."