In`ter*line" (?), v. t. [imp. & p. p. Interlined (?); p. pr. & vb. n. Interlining.] [Pref. inter- + line: cf. LL. interlineare, F. interlinéer, OF. entreligner.]

1. To write or insert between lines already written or printed, as for correction or addition; to write or print something between the lines of; as, to interline a page or a book. Swift.

2. To arrange in alternate lines; as, to interline Latin and English. Locke.

3. To mark or imprint with lines.

A crooked wrinkle interlines my brow.

• (transportation): between (or with) two airlines
       *TWA and British Airways have an interline agreement to handle each other's baggage and to accept each other's tickets.
       *I had an interline connection from Delta to AA in Dallas/Ft. Worth.