Clumsy, Unskillful, Awkward
noun, な adjective
You know how 器用 means "dextrous" and "skillful"? Well, this is when you're not those things. When you're not dextrous, you're clumsy and when you're not skillful you're unskillful.
ぶきよう
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Just keep in mind that the reading of 不 changes from ふ to ぶ. If you're clumsy you'll get a lot of boo-boos (ぶ), get it?
彼は不器用で、新しいことを学ぶのが苦手です。
He is clumsy and struggles to learn new things.
不器用ながらも、彼女は決してあきらめませんでした。
Despite her clumsiness, she never gave up.
彼は不器用な言葉で、親に感謝の気持ちを伝えました。
With clumsy words, he expressed his gratitude to his parents.