Describes doing something briskly and clearly; speaking or answering promptly and distinctly (mimetic adverb, often written in kana).
彼女は会議でいつもはきはき答えるので頼りになる。
She always answers promptly and clearly in meetings, so she's reliable.
店員さんがはきはきした対応をしてくれると気持ちがいい。
It's pleasant when shop staff respond briskly.
指示ははきはきと言ってください、曖昧だと困ります。
Please give instructions clearly and promptly; vague directions are a problem.