Definitions

1. noun

a person, especially a woman, who dresses in a dull or untidy manner, often with an air of self-importance

“The fashion critic described the celebrity as a frump at the red-carpet event.”

2. verb

to dress or behave in a dull or untidy manner

“She frumped up for the interview, not wanting to make a good impression.”

3. verb

to spoil or ruin something, especially a social occasion

“The rain frumped the outdoor wedding plans.”