PIE *dhegwh の「燃える、光る」が語源で、語源的には day, yesterday と同じ。
英語の語源
dawn
dawn: [15] Dawn was originally formed from day. The Old English word d?g ‘day’ formed the basis of dagung, literally ‘daying’, a word coined to designate the emergence of day from night. In Middle English this became daiing or dawyng, which in the 13th to 14th centuries evolved to dai(e)ning or dawenyng, on the model of some such Scandinavian form as Old Swedish daghning. Then in the 15th century the -ing ending was dropped to produce dawn. => day
dawn (v.)
c. 1200, dauen, "to dawn, grow light," shortened or back-formed from dauinge, dauing "period between darkness and sunrise," (c. 1200), from Old English dagung, from dagian "to become day," from Proto-Germanic *dagaz "day" (cognates: German tagen "to dawn;" see day (n.)). Probably influenced by Scandinavian cognates (Danish dagning, Old Norse dagan "a dawning"). Related: Dawned; dawning.
dawn (n.)
1590s, from dawn (v.).
例文
1. At dawn I woke him up and said were leaving.
明け方、私は彼を起こして、私たちが行くと言った。
2.I started work at dawn and returned only at nightfall.
私は星をかぶって働いています。
3.A breakfast will be served to those who last out till dawn ！
夜明けまで朝食が食べられるように頑張ります！
4.The business，founded by Dawn and Nigel，suffered financial setbacks.
唐とナイジェルが設立した企業は資金面でいくつかの問題に遭遇した。
5.Thousands of pounds worth of drugs were seized in dawn raids yesterday.