一段落

いちだんらく ひとだんらく

completing the first stage, reaching a point where one can pause

栄落

えいらく

flourishing and declining

一枚落ち

いちまいおち

playing shogi with a handicap of one castle (rook) or bishop

一件落着

いっけんらくちゃく

an issue being settled, a case being closed

一

ひと ひ ひい いち いっち イー

one

一軒一軒

いっけんいっけん いちけんいちけん

house to house, door to door

一言一行

いちげんいっこう

every word and act, just a word or an act

一進一退

いっしんいったい

now advancing and now retreating, ebb and flow, seesawing, taking alternately favorable and unfavorable turns

一日一夜

いちにちいちや

all day and night

一国一票

いっこくいっぴょう いちこくいちひょう

one vote per nation

一利一害

いちりいちがい

advantages and disadvantages, gain some, lose some

一朝一夕

いっちょういっせき

in a day, in a brief space of time

一世一代

いっせいちだい いっせいいちだい

once in a lifetime, the first and last occurrence (event, experience) of one's lifetime

一得一失

いっとくいっしつ

gaining some and losing some, (something having its) advantages and disadvantages

一張一弛

いっちょういっし

tension and relaxation

一汁一菜

いちじゅういっさい

one-plate meal, simple meal, austerity diet

一挙一動

いっきょいちどう

one's every action, every single move

一期一会

いちごいちえ

once-in-a-lifetime encounter (hence should be cherished as such)

一糸一毫

いっしいちごう

tiny amount