Dramatist engaged in fib senselessly (5)
I believe the answer is:
ibsen
'dramatist' is the definition.
(Ibsen is an example)
'engaged in fib senselessly' is the wordplay.
'engaged in' indicates the answer is hidden within the clue.
'IBSEN' can be found hidden inside 'fib senselessly'.
(Other definitions for ibsen that I've seen before include "Author of The Master Builder, d. 1906" , "Dramatist, author of Peer Gynt" , "Norwegian playwright, d. 1906" , "6 24 113 [SCAN-DIN-AVIAN] writer" , "not one for 'All work and no play ...'" .)