Longman Dictionary of Contemporary English
Wiktionary
n. Alternative expression for junk mail.
WordNet
n. advertising sent directly to prospective customers via the mail
Usage examples of "direct mail".
It was a suburban backwater, half its units empty, the rest unobtrusive in their telemarketing and direct mail and small-scale manufactures.
But direct mail coverage followed by telephone calls on the day of the meeting are your best bet.
In this way he compiled enormous mailing lists, which he sold to other fund-raisers, to direct mail houses, to test-market organizations, to the subscription departments of various print media and to government agencies.
That's great news for starving personal-injury attorneys, since ambulance-chasing by direct mail is more fuel efficient and less hectic than the old way.
Magazines and newspapers and direct mail business will boom, and that'll ease the pain in the ad agencies.