The definition of erstwhile is something from an earlier time.
An example of something erstwhile is a girl who was your best friend as a child.
In the past; at a former time; formerly.
Former: our erstwhile companions.
- In Metal Gear Solid 4, our erstwhile special-ops hero, Solid Snake, is now a grizzled veteran facing legions of bipedal robots - and doubtlessly, he also is up against a cadre of superpowered bad guys and the usual save-the-world situation.
- Rather than sinking without a trace, as many erstwhile efforts from talented but unknown teams have historically done, Serious Sam won a raft of gaming awards, including GameSpot's game of the year, and sold quite well.
- Dixie Cooney was a duck out of water in Pine Valley, but her intrinsic naivety and sweetness appealed to the rascal Tad and redeemed him from bad boy to erstwhile hero.
- Brothers Caleb, Nathan and Jared Followill and cousin Matthew Followill are the offspring (and nephew) of erstwhile traveling Pentecostal preacher, Leon Followill.
- According to a source close to the erstwhile prankster, Steve-O was admitted to Cedars-Sinai in order to log some recovery time from his "reckless lifestyle."