"M*A*S*H” star (4)
'mash star' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alda that I've seen before include "American actor" , "Alan ---, M.A.S.H. actor" .)
(Other definitions for farr that I've seen before include "Tommy - - , Welsh boxer" , "Tommy - - , Welsh heavyweight champion" .)