Lift, and make straighter with the other hand (7)
I believe the answer is:
lighten
'lift' is the definition.
(I've seen this before)
'with the other hand' is the wordplay.
'with' is an insertion indicator.
'other' indicates an anagram.
'hand' becomes 'lign' (I can't explain this - if you can you should give a lot more credence to this answer).
'the' is an anagram of 'hte'.
'hte' put inside 'lign' is 'LIGHTEN'.
'and make straighter' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for lighten that I've seen before include "Make less dark or heavy" , "make fairer" , "Make less serious" , "Reduce load" , "Become less serious" .)