細 slender

I SIGH because I can't get any more slender.

Wrap the string once round the whole rice field and just contract it until the field gets slender.

details ★☆☆☆☆
詳 (expert) + 細 (slender) = 詳細 (details)

the details or particulars of a thing

cell ★☆☆☆☆
細 (slender) + 胞 (cell) = 細胞 (cell)

a cell, like an amoeba or a brain cell.

petty, insignificant ★☆☆☆☆

small, in the sense of petty or trifling, insignificant. Don't sweat the small stuff. Don't bother me with such trivial complaints. Here's a good phrase to learn: "些細な事に気を使うな！”　（ささいなことにきをつかうな）= Don't worry about such trivial things!