IPA: //ˈmʌdflæp//
KK: /mʌdflæp/
A flat piece of material attached near the wheels of a vehicle to stop mud and dirt from splashing onto the body of the vehicle.
The truck had a new mudflap installed to keep the paint clean.
Mudflap is formed from "mud" (from Old English "mudd", meaning wet earth or soft soil) and "flap" (from Middle English "flappe", meaning to move or swing loosely). The word "mudflap" refers to a flexible piece that hangs down to protect against mud splashes from vehicles.
Think of 'mud' as wet earth and 'flap' as something that swings down — a mudflap is a piece that hangs down to keep mud from splashing.
No commonly confused words.