Tolerating a heartless order (7)
I believe the answer is:
abiding
'tolerating' is the definition.
('abide' can be a synonym of 'tolerate')
'a heartless order' is the wordplay.
I cannot really see how this works, but
'a' is present in the answer.
'order' could be 'bid' (I've seen this in another clue) and 'bid' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for abiding that I've seen before include "Stopping" , "Dwelling; enduring, lasting" , "Remaining or residing" , "firm" , "Durable, lasting" .)