Coin once held by Indian nabobs? (4)
I believe the answer is:
anna
'coin' is the definition.
(I have seen 'Old coin' mean 'anna' so perhaps 'coin' could also mean 'anna')
'held by indian nabobs?' is the wordplay.
'held by' says the answer is hidden in the clue.
'ANNA' can be found hidden inside 'indian nabobs'.
'once' is the link.
(Other definitions for anna that I've seen before include "and eleven, twenty four across heroine" , "She's a woman, whichever way you look at it" , "Girl's name (palindrome)" , "___ Pavlova, Russian dancer, d. 1931" , "Book by Tolstoy" .)