B&B in valley beside river — one not fully occupied? (7)

I believe the answer is:
dabbler
'one not fully occupied?' is the definition.
I can't judge whether this definition defines the answer.
'bb in valley beside river' is the wordplay.
'in' means one lot of letters goes inside another.
'valley' becomes 'dale' (dale is a kind of valley).
'beside' means one lot of letters go next to another (I've seen this in other clues).
'river' becomes 'r' (abbreviation).
'bb' put inside 'dale' is 'dabble'.
'dabble'+'r'='DABBLER'
Can you help me to learn more?
(Other definitions for dabbler that I've seen before include "amateur" , "Dilettante" , "Someone with passing interest" .)
