Possibly ram Greek character (6)
I believe the answer is:
lambda
'greek character' is the definition.
(letter from the Greek alphabet)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lambda that I've seen before include "Steps taken" , "The 11th letter of the Greek alphabet" , "character from Greece" , "Eleventh Greek letter" , "Greek character" .)