as sin(redirected from something as sin)
A phrase used as an intensifier for a negative description or situation. I wouldn't buy that painting, it's ugly as sin.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
— as sinhaving a particular undesirable quality to a high degree. informal
1991 Robert R. McCammon Boy's Life Everybody knew Saxon's Lake was as deep as sin.
Farlex Partner Idioms Dictionary © Farlex 2017
n. synthetic marijuana. (Drugs. From synthetic.) Most of this stuff the kids put down good money for is not sin but angel dust.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
Completely or extremely: He is guilty as sin.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.