IPA: /ˈspiːdiər/
KK: /ˈspidɪər/
Faster than something else; having a higher speed.
The new train is speedier than the old one.
Speedier → It is formed from "speed" (from Old English *spēd*, meaning success or prosperity) and the suffix "-ier" (meaning more). The word "speedier" means more speedy or having greater speed.
Think of 'speed' as success in moving quickly, and the '-ier' indicates more of that quality. So, speedier means having more speed.