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not exceeding ...; not more than ...; ... and under; ... and below; ... or fewer
below (a standard, level, etc.); under; beneath; less than
the following; the below-mentioned; the rest; followed by ...
including ...; ... and other (employees, officials, etc.)
十歳已下の子供は無料だ。
Children ten and under are free.
百円已下の商品を探した。
I looked for products under 100 yen.
三回已下の出席では不合格になる。
Attending three or fewer times results in a fail.