noun
wheel
A2
Rad (das) means 'wheel'—a circular rotating part of vehicles or machines. Plural: Räder (umlaut); genitive singular des Rades. Neuter noun with irregular plural formation (Räder). Common in compounds (Fahrrad) and idioms. No special preposition. Used for wheels, gears, and figurative 'cycles' contexts.
Examples
Das Rad dreht sich.
The wheel is turning.
Das Rad des Fahrrads ist kaputt.
The bicycle's wheel is broken.
Der Mechaniker tauschte das Rad am Fahrrad, nachdem der Kunde den Schaden gemeldet hatte, damit die Tour weitergehen konnte.
The mechanic replaced the wheel on the bicycle after the customer had reported the damage so that the tour could continue.
Details
Mnemonics
a bicycle wheel spinning on the road
rad -> 'rod' (wheel axle) as a visual anchor
das = neuter — imagine a small neutral wheel in a box
Notes
Can mean wheel or (colloquially) bicycle in some contexts; plural: Räder.