noun, verbal noun
When you make writing, what are you doing? Simply put, you're writing. If you want to be fancier about it, you could say this is composition.
Note that 作文 often refers to the end result of a writing process, like a finished essay, rather than the writing process itself. It’s also commonly associated with various writing tasks assigned to students in Japanese elementary or middle school.
This is a jukugo word, which usually means on'yomi readings from the kanji. Since both 文 and 作 have two on'yomi readings, here's a mnemonic to help you remember which ones to use:
You can't stop writing compositions about sacks 'n' buns (さくぶん). You're obsessed with them. You've been writing essay after essay about sacks 'n' buns. Stop writing about sacks 'n' buns!
A seven-year-old boy's essay became a book.
In first grade writing class, we wrote on the theme of "cherry blossom viewing".
I corrected composition errors with a fat red pen.