1. a person or thing that fouls or makes something foul or dirty

1. more foul; more offensive, disgusting, or unpleasant in smell, taste, or appearance
Usage: comparative form of foul
2. more foul; more wicked, immoral, or abusive in language or behavior
Usage: comparative form of foul

Examples

• The fouler of the two rooms needed immediate cleaning.
• This water is fouler than it was last week.
• His fouler mood made everyone uncomfortable.
• The fouler language in the second draft was removed before publication.
• Industrial polluters are the foulers of our environment.
• The fouler the weather became, the fewer people ventured outside.