American beer and most lager turns out to be rather pleasant (9)
I believe the answer is:
agreeable
'rather pleasant' is the definition.
'agreeable' can be an answer for 'pleasant' (similar in meaning). I am not certain of the 'rather' bit.
'american beer and most lager turns out' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'and' means one lot of letters go next to another.
'most' means to remove the last letter.
'turns out' indicates an anagram.
'lager' with its final letter taken away is 'lage'.
'beer' after 'lage' is 'lagebeer'.
'lagebeer' is an anagram of 'greeable'.
'a'+'greeable'='AGREEABLE'
'to be' is the link.
Can you help me to learn more?
(Other definitions for agreeable that I've seen before include "In harmony; pleasant" , "Pleasant, pleasing" , "sympathetic" , "Willing - nice" , "Cordial" .)