crowded: having a lot of people or too many people
We made our way through the crowded streets.
a crowded bar
The main beach can get really crowded in summer.
London was very crowded.
crowded with somebody In the spring the place is crowded with skiers.
uncrowded: not full of people
The beach was pleasantly uncrowded.
I don't think "uncrowded" is a complete opposite of "crowded". "Uncrowded" is simply "not full of people", it does not mean "very few people".
The opposite of "crowded" is "very few people"
What is the opposite of "crowded" ?