To write something exactly as it is said or written in another place or source. A noun or pronoun can be used between "copy" and "down." Did you copy down the instructions the boss gave for this project?Be sure to copy your homework down—it's written on the blackboard.
copy something down (from someone or something)
to copy onto paper what someone says; to copy onto paper what one reads. Please copy this down from Tony.Ted copied down the directions from the invitation.Jane copied the recipe down from the cookbook.
copy down
v.
To write something exactly as it is said or written somewhere else; transcribe something: I'll be out tomorrow, so please copy down what the teacher says. Copy the instructions down so you don't forget them.