A foundation that's lower (5)

I believe the answer is:

abase

'that's lower' is the definition.
(I've seen this before)

'a foundation' is the wordplay.
'foundation' becomes 'base' (synonyms).
'a'+'base'='ABASE'

(Other definitions for abase that I've seen before include "Degrade (oneself)" , "Belittle, degrade" , "Cast down" , "put to shame" , "Humiliate" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app