Definition & Meaning of "dippy"in English

What is the origin of the term "dippy" and how is it used?

"Dippy" appeared in the early 20th century, formed from the word "dip," which was used figuratively to suggest someone was mentally "submerged" or not fully alert. It came to describe a person who is silly, scatterbrained, or lacking good judgment. The term is used in informal speech, often teasingly or affectionately. It is mildly derogatory but generally playful rather than harsh.