Meaning:
"攻" means to "attack," "气" means "spirit," and "十足" means "full of." This term, which means "masculine," has been recently used on posh girls who show determination and strength in their character.
Example
A: 你姐姐还在政府当公务员吗？
Nǐ jiějiě hái zài zhèngfǔ dāng gōngwùyuàn ma?
Is your sister still working as a public servant?
B: 没有，她去年就辞职了，现在自己开一家在线旅游公司。
Méiyǒu, tā qùnián jìu cízhì le, xiànzài zìjǐ kāi yījiā zàixiàn lǚyóu gōngsī。
No. She quit her previous job last year. Now she is running her own business -- an online travel agency.
A: 她一直是很有主见的女生，什么事情说干就干。
Tā yīzhí shì hěn yǒu zhǔjiàn de nǚshēng, shénme shìqíng shuōgànjìugān。
She always has her own opinions about things, and will put her words into actions.
B: 是啊，攻气十足。
Shì a, gōngqì shízú。
Indeed, she's kind of powerful and tough.
(Edited by Stephanie Yang)