(a copy of) a document that travels in electronic form along a phone line and is then printed on paper

I'll send you a fax with the details of the proposal. 我会把提案的细节用传真发给您。

a device or system used to send and receive documents in electronic form along a phone line

I'll send you the agenda by fax. 我会把议程用传真发给您。

Do you have a fax at home? 你家里有传真机吗？

to send a document using a fax machine

I'll fax it (through/over/across) to you. 我会把它传真给您。

[ + two objects ] Fax me your reply/Fax your reply to me. 请用传真答复。