Stop by the side of the road to pick up old females (4,3)
I believe the answer is:
pull off
'stop by the side of the road' is the definition.
I can't judge whether this definition defines the answer.
'pick up old females' is the wordplay.
'pick up' becomes 'pull' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'females' becomes 'ff' (an abbreviation for female written twice).
'pull'+'o'+'ff'='PULL-OFF'
'to' is the link.
Can you help me to learn more?
(Other definitions for pull off that I've seen before include "Successfully execute" , "Achieve a goal" .)