Definition of "spiny" [spin•y]

• Bearing or covered with spines, thorns, or similar stiff projections. (adjective)
• Shaped like a spine. (adjective)
• Difficult; troublesome. (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.

• "I mean, discipline -- if ever you'd known discipline -- in the police if you like -- anything -- anywhere where there's what we used to call spiny de cor."
• "The Houses of Parliament runs one; another casts its spooky glow over Buckingham Palace gardens a sub- Saharan moth called the spiny bollworm puzzled scientists until they discovered a state delegation from Tanzania had stayed with the Queen the week before."
• "Among the fossils found here are acanthodians - the so-called "spiny sharks" which are thought to be the oldest vertebrates to possess true teeth - and what Blais and colleagues consider to be a chondrichthyan, or an early member of the group of cartilaginous fish which includes sharks, skates, and rays today."