As I see it, I'm bony, active and very well (2,2,4)
I believe the answer is:
in my book
'as i see it' is the definition.
(I've seen this before)
'i'm bony active and very well' is the wordplay.
'active' indicates anagramming the letters (the letters are active/moving).
'and' says to put letters next to each other.
'very well' becomes 'OK' (synonyms).
'im'+'bony'='imbony'
'imbony' is an anagram of 'inmybo'.
'inmybo'+'ok'='IN MY BOOK'
(Other definitions for in my book that I've seen before include "To my way of thinking" , "As I see it" , "How to describe writer's published words" , "place for autobiographical details" , "as far as I'm concerned?" .)