noun
cyclist, bicycle rider
B1
Radfahrer means cyclist or bicycle rider. It is a masculine noun (der Radfahrer). The plural is Radfahrer, identical to singular. Declension includes genitive des Radfahrers (singular) and nominative die Radfahrer (plural). No irregular plural. Refers to people who ride bicycles, commonly.
Examples
Der Radfahrer trug einen Helm.
The cyclist wore a helmet.
Als Fahrradfreund kennt jeder Radfahrer die besten Radwege der Stadt.
As a bike enthusiast, every bicycle rider knows the best bike paths in the city.
Die Autofahrerin bremste, weil sie den Radfahrer sah.
The (female) driver braked because she saw the cyclist.
Details
Mnemonics
Imagine a person riding a bicycle with a helmet and a visible wheel (Rad) to remember Radfahrer
Starts with 'Rad' (wheel) — think 'rad' as in wheel + 'fahrer' driver
der Radfahrer — picture a male rider labeled 'der' to anchor the masculine gender
Notes
Radfahrer is a commonly used compound noun for someone riding a bicycle. Feminine form can be 'die Radfahrerin' for a female rider.