1To form, make up, or constitute a whole out of parts or elements. Common in set phrases such as 群れをなす (form a flock), 列をなす (form a line), and 意味をなす (make sense).
渡り鳥が群れを成して南へ飛んでいく。
The migratory birds form a flock and fly south.
開店前から店の前に長い列を成していた。
A long line had formed in front of the store even before it opened.
文章が支離滅裂で、まったく意味をなさない。
The writing is so incoherent that it makes no sense at all.
これらの建物が一体となって美しい景観を成している。
These buildings together form a beautiful landscape.
2To build up or amass (e.g., a fortune); to create or establish something through effort, as in 財を成す (make a fortune).
彼は貿易で財を成した。
He made a fortune in trade.
一代で巨万の富を成した実業家の伝記を読んだ。
I read the biography of an entrepreneur who amassed an immense fortune in a single generation.
祖父は裸一貫から事業を成した。
My grandfather built up his business from nothing.
3To accomplish or achieve something; to gain (fame, success). As in 名を成す (make a name for oneself) and 偉業を成す (achieve a great feat).
彼は学者として名を成した。
He made a name for himself as a scholar.
その登山家は前人未到の偉業を成した。
That mountaineer achieved an unprecedented feat.
長年の努力の末に、大きな仕事を成した。
After years of effort, he accomplished a great work.
4To turn one thing into another, or to treat A as B. Used in the somewhat formal pattern 〜を〜と成す.
彼は逆境を好機と成した。
He turned adversity into opportunity.
過去の失敗を糧と成して、彼は再び立ち上がった。
Making his past failures into nourishment, he rose again.
5To do, carry out, or commit (an action). In this sense it is also written 為す and very often written in kana as なす, as in なすべきこと (what one should do) and なす術もない (be at a loss for what to do). (See also 為す.)
今、我々がなすべきことを冷静に考えよう。
Let's calmly consider what we should do now.
なす術もなく、ただ時間が過ぎるのを待った。
At a loss for what to do, I just waited for time to pass.
人に害をなすような行為は許されない。
Acts that do harm to others cannot be tolerated.
6A suffixal use that attaches to the -masu stem of a verb, adding the sense of doing the action deliberately. No longer productive; it survives only in fossilized compounds such as 見なす (to regard as) and もてなす (to entertain).