1Round; circular or spherical — describing something shaped like a circle or sphere, or having rounded edges. 丸い usually refers to ball-shaped objects, while 円い usually refers to disc-shaped ones.
ボールは丸い形をしている。
A ball has a round shape.
テーブルは丸い方が話しやすい。
A round table makes conversation easier.
地球は完全な球体ではないが、ほぼ丸い形をしている。
The Earth is not a perfect sphere, but it is roughly round.
満月は夜空に丸く浮かんでいた。
The full moon hung round in the night sky.
2Curved; smooth — having rounded contours or lacking sharp angles.
この家具は角が丸くてけがをしにくい。
This furniture has rounded corners and is less likely to cause injuries.
丸いフォルムのスマートフォンが人気だ。
Smartphones with rounded forms are popular.
年をとって、彼の背中は少し丸くなった。
As he aged, his back became slightly rounded.
3Harmonious; mild or amiable — describing a calm, conciliatory mood (as in 「丸く収まる」, 'to settle things amicably').
彼は丸い人柄で、誰とでも話しやすい。
He has a gentle personality and is easy to talk to.
意見の食い違いは結局丸く収まった。
The disagreement was ultimately settled amicably.