<p><strong>Verb</strong></p><ul><li>(used with object) To write or insert (words, phrases, etc.) between the lines of writing or print.</li><li>To mark or inscribe (a document, book, etc.) between the lines.</li><li>To transfer (freight) from one carrier to another in the course of shipment.</li></ul><p><strong>Adjective</strong></p><ul><li>Involving or indicating a transfer of passengers or freight from one carrier to another during travel or shipment: interline flights.</li><li>Of or relating to transactions between competing carriers, especially airlines, by which passengers, baggage, and freight are transferred from one carrier to another using only one ticket or one check-in procedure from departure point to destination.</li></ul>