More than one thought I would relapse, regularly (5)
I believe the answer is:
ideas
'more than one thought' is the definition.
('idea' can be a synonym of 'thought')
'i would relapse regularly' is the wordplay.
'i would' becomes 'id'.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'relapse' are 'eas'.
'id'+'eas'='IDEAS'
(Other definitions for ideas that I've seen before include "plans" , "Thoughts, perceptions" , "Aside (anag.)" , "Thoughts, concepts" , "Thoughts, maybe creative" .)