Plus wandering into one myself, on a caprice (7)
I believe the answer is:
impulse
'a caprice' is the definition.
('impulse' can be a synonym of 'caprice')
'plus wandering into one myself' is the wordplay.
'wandering' indicates anagramming the letters.
'into' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'myself' becomes 'me'.
'plus' with letters rearranged gives 'puls'.
'i'+'me'='ime'
'puls' inserted within 'ime' is 'IMPULSE'.
'on' is the link.
(Other definitions for impulse that I've seen before include "Miles up (anag)" , "Sudden or instinctive desire" , "Sudden urge to do something" , "A sudden inclination to act (7)" , "A sudden urge or whim" .)