Kyūjitai form of 三位一体 (“Trinity”)

(obsolete) being surprised twice / (obsolete) more specifically, describes the appearance of a woman who has a beautiful figure from behind but has an ugly face

(Christianity) the Trinity

(figuratively) being carefree and unaware of an imminent danger

(figuratively) a narrow world view based on limited experience

three days ago

“a hundred days of sermonizing, one fart” → a metaphor for how something that one has put great effort into can come to nothing after even a slight mistake, much as a hundred days of serious spiritual study can be lost to the winds

a depressor septi nasi

the famous of the “one hundred poems by one hundred poets” anthologies, compiled by Fujiwara no Teika in c. 1235, used in the basis of certain card games

a journey of a thousand miles begins with a single step