Take up half the load as you choose (5)
I believe the answer is:
adopt
'choose' is the definition.
(adopting is a kind of choosing)
'take up half the' is the wordplay.
'take' becomes 'ado' (I can't explain this - if you can you should give a lot more credence to this answer).
'half' means to take half the letters.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'up' halved is 'p'.
'ado'+'p'+'t'='ADOPT'
'load as you' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for adopt that I've seen before include "Take up, follow" , "Accept as one's own" , "Take responsibility for" , "Acquire" , "Formally approve" .)