This is the 6814th most frequent Japanese word.
フラフラ
Unsteady, dizzy, or aimless.
Here, "フラフラ" is used to describe the state of exhaustion or dizziness due to lack of sleep.
昨日夜更かしをして、今日はフラフラしている。
I stayed up late last night, so I'm feeling dizzy today.
In this sentence, "フラフラ" exemplifies unsteady movement, likely due to physical fatigue.
炎天下で運動した後、彼はフラフラ歩いていた。
After exercising under the hot sun, he was walking unsteadily.
Here, "フラフラ" conveys the ongoing and general state of tiredness or lethargy.