Inauguration Day
noun [ C usually singular ] uk/ɪ.nɔː.ɡjʊˈreɪ.ʃən ˌdeɪ/ us/ɪ.nɑː.ɡjʊˈreɪ.ʃən ˌdeɪ/
美国总统就职日（美国总统从前任接过权力，正式就职，举行就职仪式的日子）
in the US, the day when a person officially becomes president in a special ceremony and takes responsibility from the previous president