Afternoon meal Athena regularly provides (3)
I believe the answer is:
tea
'afternoon meal' is the definition.
(meal eaten in the afternoon)
'athena regularly provides' is the wordplay.
'regularly provides' means one should take alternating letters.
The alternate letters of 'athena' are 'TEA'.
(Other definitions for tea that I've seen before include "Darjeeling, e.g." , "Light afternoon repast" , "grass" , "brewer's product" , "leaves much to be desired?" .)