This is the 5711th most frequent Japanese word.
ださ
Uncool; tacky; lame.
The word 'ださい' is used as an adjective meaning 'uncool' or 'tacky' to describe clothing.
この服、ださいね。
These clothes are uncool.
Here, 'ださい' is used to describe someone's thinking as old-fashioned or not trendy.
彼の考え方はちょっとださい。
His way of thinking is a bit outdated.
In this sentence, 'ださい' is applied to a design indicating that it is aesthetically lacking or not stylish.