The word "Gainsborough" primarily refers to a famous English portrait and landscape painter named Thomas Gainsborough, who lived from 1727 to 1788. He is well-known for his beautiful paintings and is considered one of the great artists of the 18th century.
In art discussions, you might hear people say, "This painting has a Gainsborough quality," meaning it has similar features or styles to Gainsborough’s works, such as soft colors and elegant compositions.
There aren't direct synonyms for "Gainsborough," as it's a proper noun, but you might refer to similar artists (like Reynolds or Van Dyck) when discussing portrait painting from the same era.
There are no specific idioms or phrasal verbs that include "Gainsborough," since it is a proper noun. However, you could use phrases like "in the style of Gainsborough" to describe art that resembles his work.
When using "Gainsborough," remember it mainly refers to Thomas Gainsborough, the artist.