Crossword Genius

Joke by one in senile dotage (4)

Ross

I believe the answer is:

gaga

'in senile dotage' is the definition.
(I've seen this before)

'joke by one' is the wordplay.
'joke' becomes 'gag' ('gag' can be a synonym of 'joke'**).
'by' means one lot of letters go next to another.
'one' becomes 'a'.
'gag'+'a'='GAGA'

(Other definitions for gaga that I've seen before include "In repetitive slang, senile or crazy" , "Barmy joke, third in cracker" , "In senile dotage" , "bananas" , "Lady < > in a senile" .)

I've seen this clue in The Telegraph.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.