frank
/fɹæŋk/noun
The right, held mainly by governments, to send mail without paying postage.
Example sentences
- “Members of parliament once used the frank to send letters at no cost.”
- “All of the senator's official correspondence went out under his frank.”
The common word is the adjective: a frank discussion is bluntly honest, and 'to be frank' warns that plain speech is coming. This postal sense survives in 'franking machine'.