1. when you get weaseled or bamboozled into doing something that you wouldn't do otherwise
2. when you give into doing what someone wants just becasue you don't want to hear them complain and bitch anymore

Adj. Something that is expected to have a long lifespan by virtue of having existed for a long time, based on the lindy effect, named for the New York restaurant Lindy's, coined by Albert Goldman and popularized by Nassim Taleb.