MAINLINE Meaning of MAINLINE in English mainlin|e BrE AmE ˈmeɪn laɪn ˌ•ˈ• ▷ mainlin|ed d▷ mainlin|er/s ə/z AmE \ ə r/z▷ mainlin|es z▷ mainlin|ing ɪŋ Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012