Bald man almost mistaken for character in Greek tragedy? (6)
I believe the answer is:
lambda
'character in greek tragedy?' is the definition.
(letter of the Greek alphabet)
'bald man almost mistaken' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'mistaken' is an anagram indicator.
'bald'+'man'='baldman'
'baldman' with its final letter taken away is 'baldma'.
'baldma' anagrammed gives 'LAMBDA'.
'for' is the link.
(Other definitions for lambda that I've seen before include "Greek character" , "Not one of our characters" , "The 11th letter of the Greek alphabet" , "Teasing entertainer" , "Greek letter - am bald (anag)" .)