1. Costing nothing
   - complimentary, free, gratis, gratuitous

See also: unpaid

• mailboat
• mailbox
• maildrop
• mailed
• mailer
• mailing
• mailing address
• mailing list
• mailing-card
• Maillol
• maillot
• mailman
• mailshot
• mailsorter
• maim
• maimed
• maimer
• Maimonides
• main
• main clause
• main course
• main deck
• main diagonal
• main drag
• main entry word