Thoughts - even wild pecans! (5)
I believe the answer is:
ideas
'thoughts' is the definition.
('idea' can be a synonym of 'thought')
'even wild pecans' is the wordplay.
'even' means one should take alternating letters (even-numbered letters are used).
'wild'+'pecans'='wildpecans'
The alternate letters of 'wildpecans' are 'IDEAS'.
(Other definitions for ideas that I've seen before include "Brain waves" , "Thoughts, concepts" , "Theories" , "Aside (anag.)" , "Brainwaves" .)