Superlative form of 'couth'; the most sophisticated or refined.
Formed by adding the superlative suffix '-est' to 'couth,' following standard English rules; created as part of the broader 'couth' back-formation in the 20th century.
Using 'couthest' is almost comedic—it's like saying 'the most of a made-up word'—which might be why you rarely hear it, even though it's technically correct English.
Complete word intelligence in one call. Free tier — 50 lookups/day.