Take in tenant periodically (3)
I believe the answer is:
eat
'take in' is the definition.
(to eat is to take in food)
'tenant periodically' is the wordplay.
'periodically' means one should take alternating letters (letters must be selected 'every so often').
The alternating letters of 'tenant' are 'EAT'.
(Other definitions for eat that I've seen before include "Feed" , "and 27: Be humiliated" , "Consume for tea" , "Take food" , "Devour" .)