Old lady cheers a couple of home guards for support (8)
I believe the answer is:
Here is my best explanation:
'support' is the definition.
(I've seen this before)
'old lady cheers a couple of home guards' is the subsidiary indication.
'old lady' becomes 'ma'.
'cheers' becomes 'ta' (I've seen this in other clues).
'a couple of' says to double the letters.
'home' becomes 'in' ('he's home' can mean 'he's in').
'guards' indicates putting letters inside.
'in' duplicated is 'inin'.
'ta' placed inside 'inin' is 'intain'.
'for' is the link.
(Other definitions for maintain that I've seen before include "Keep up repairs", "Preserve or insist", "Keep (at the same level)", "Keep (a building) in good condition", "Assert", "Keep in existence or in repair", "Keep in a certain state", "To keep up", "Support" and "Keep - support".)