spam

Concise Oxford English Dictionary © 2008 Oxford University Press:
spam/spam/

▶noun

• 1 (Spam) trademark a tinned meat product made mainly from ham.

• 2 irrelevant or inappropriate messages sent on the Internet to a large number of newsgroups or users.

▶verb send the same message indiscriminately to (large numbers of newsgroups or users) on the Internet.

– derivatives
spammer noun,
spamming noun.

– origin 1930s: appar. from sp(iced h)am; the Internet sense prob. derives from a sketch by the British ‘Monty Python’ comedy group, set in a cafe in which every item on the menu includes Spam.