This is the 67th most frequent Marathi word.
दर
Rate; cost; value; frequency.
In this sentence, 'दर' means 'price' and is used to indicate the cost of something.
दुधाचा दर वाढला आहे.
The price of milk has increased.
Here, 'दर' means 'every', indicating the frequency of an event happening over time.
दर दहा मिनिटांनी ट्रेन स्टेशनवर येते.
The train arrives at the station every ten minutes.
In this context, 'दर' is used to mean 'every', highlighting emphasis on each occurrence of an event.