franking
/ˈfræŋkɪŋ/noun
mass noun
1- the action of franking a letter or parcel邮戳盖于（信, 包裹）（表示邮资已付或免费投递）：
as modifier a franking machine.邮资机。
1.1
- count noun an official mark or signature on a letter or parcel to indicate that postage has been paid or does not need to be paid免费投递戳（或签字）; 邮资已付戳（或签字）。