Any unethical lawyer, or one who is too aggressive in getting clients; shyster(late 1800s+)
A lawyer or lawyer's helper who urges accident victims to sue for damages, negligence, etc (1900s+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with ambulance-chasing
An attorney who seeks to profit from someone's injury or accident; also, an inferior lawyer. For example, Karen refused to join any law firm that included ambulance chasers. The practice of suing for damages on behalf of the injured person in exchange for a contingency fee—usually a large percentage of the amount so won—may be older, but this derogatory term began to be used for lawyers who actively sought out individuals injured in accidents who required an ambulance.
[ ; late 1800s