Learned about boomerangs Buddhist men regularly used (7)
I believe the answer is:
erudite
'learned' is the definition.
(erudite means learned or well-read)
'about boomerangs buddhist men regularly used' is the wordplay.
'about' becomes 're' (regarding).
'boomerangs' shows that the letters should be reversed in order (letters rebound back like a boomerang).
'regularly used' means one should take alternating letters (letters selected on a regular basis).
'buddhist'+'men'='buddhistmen'
The alternate letters of 'buddhistmen' are 'udite'.
're' written backwards gives 'er'.
'er'+'udite'='ERUDITE'
(Other definitions for erudite that I've seen before include "'Learned, knowledgeable (7)'" , "Showing profound knowledge" , "academic" , "Learned and scholarly" , "Having or showing great knowledge or learning" .)