1The position below, down, or underneath something — the most basic spatial sense of 下 (read した). One of the first words a learner encounters. Also used for younger siblings or children, as in 下の妹 (younger sister) or 三つ下の弟 (a brother three years younger).
机の下に猫がうずくまっている。
A cat is curled up under the desk.
下を見ないで、まっすぐ前を見て歩こう。
Don't look down — walk with your eyes straight ahead.
うちには三つ下の妹がいます。
I have a sister three years younger than me.
下のお子さんは何歳ですか?
How old is your younger child?
2The bottom — the lowest point or end of a range, container, or ranking (e.g., the bottom of a list, the bottom of a box).
リストの一番下に名前を書き加えてください。
Please add your name at the very bottom of the list.
引き出しの一番下に古い手紙を見つけた。
I found an old letter at the bottom of the drawer.
順位は下から数えた方が早い成績だった。
His ranking was the kind it's faster to count from the bottom.
3Directly beneath; underneath — the position immediately under something that covers or shelters, as in 屋根の下 (under the roof), 橋の下 (under the bridge), or 看板の下 (under the sign).
突然の雨で、店の軒下で雨宿りした。
It started raining suddenly, so we took shelter under the eaves of the shop.
橋の下を小さなボートが通っていく。
A small boat is passing under the bridge.
看板のすぐ下に住所が小さく書いてある。
The address is written in small print just below the sign.
4In document layout, 'just below' or 'following below' — used in expressions like 下に続く (continues below), 下から順に (starting from the bottom), or 下記 (the following / as below).
詳しい説明は下に続きます。
A detailed explanation continues below.
ランキングは下から順に発表します。
We'll announce the rankings starting from the bottom.
5Lower in rank, position, or age; a subordinate or junior. Used in phrases like 上司の下で働く (work under one's boss), 一階級下 (one rank lower), or 年下 (younger).
彼は部長の下で五年間働いた。
He worked under the department head for five years.
上の立場の人は、下の意見にも耳を傾けるべきだ。
Those in higher positions should listen to the opinions of those below them.
年齢は彼の方が一つ下だが、入社は早い。
He's a year younger, but he joined the company earlier.
6Trade-in — exchanging an old item for credit toward a new purchase. In modern Japanese, the standalone 下 is essentially never used in this sense; it appears only in the compound 下取り (shitadori), as in 下取りに出す (trade in) or 下取り価格 (trade-in value).
7A prefix-like usage meaning 'preliminary' or 'preparatory'. Forms many compounds for the stage before the main one — 下準備 (shitajunbi, advance preparation), 下調べ (shitashirabe, preliminary research), 下見 (shitami, preview/site visit), 下書き (shitagaki, rough draft), 下塗り (shitanuri, undercoat).
料理を始める前に、野菜の下準備をしておこう。
Let's do the prep work on the vegetables before we start cooking.
出張先のことを少し下調べしておいた。
I did a little advance research on the place I'll be visiting for work.
新居の下見に行ってきた。
I went to see the new place I'm thinking of moving into.