IPA: //ˈspiːdər//
KK: /ˈspidər/
A person who drives a vehicle faster than the allowed speed limit.
The police caught a speeder on the highway going 100 miles per hour.
Speeder → It is formed from "speed" (from Old English "spēd", meaning success or prosperity) and "-er" (meaning a person who). The word "speeder" refers to a person who moves quickly or is fast.
Think of someone who is associated with 'speed' — the '-er' indicates a person, so a speeder is someone who is fast.