mail

1 mail /ˈmeɪl/ noun
1 mail
/ˈmeɪl/
noun
Britannica Dictionary definition of MAIL
[noncount]
1 
◊ Mail is used in British English but it is much more common in U.S. English. The usual word in British English is post.
: the system used for sending letters and packages from one person to another
— called also (chiefly British) post
— see also airmail, direct mail, registered mail, return mail, surface mail, voice mail
2 
: letters or packages sent from one person to another
— called also (chiefly British) post
— see also fan mail, junk mail, snail mail
3 
: 1e-mail

the mails

chiefly US, law, formal
: the system used for sending letters, packages, etc. : a nation's postal system
2 mail /ˈmeɪl/ verb
mails; mailed; mailing
2 mail
/ˈmeɪl/
verb
mails; mailed; mailing
Britannica Dictionary definition of MAIL
[+ object] chiefly US
: to send (something, such as a letter or package) by mail
3 mail /ˈmeɪl/ noun
3 mail
/ˈmeɪl/
noun
Britannica Dictionary definition of MAIL
[noncount]
: a kind of protective clothing (called armor) that is made of many small pieces or rings of metal which are linked together — see also chain mail