Great beer Ruddles initially promoted (5)
I believe the answer is:
large
'great' is the definition.
(similar in meaning)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for large that I've seen before include "Big, outsize" , "Stout" , "Copious" , "Of considerable size or extent" , "Comprehensive" .)