Couple seen in Fort Worth (3)
I believe the answer is:
two
'couple' is the definition.
(two people or things)
'in fort worth' is the wordplay.
'in' indicates a hidden word.
'TWO' is hidden in the letters of 'fort worth'.
'seen' acts as a link.
(Other definitions for two that I've seen before include "A pair (3)" , "Old song 'Tea for . . .'" , "II" , "Figure" , "Couple, brace" .)