クラッと

く

ら

っ

と

Meanings

1

adverb, noun or participle which takes 'suru'

dizzyingly; with one's head swimming

onomatopoeic or mimetic word

Describes a sudden feeling of dizziness or lightheadedness, often from standing up quickly, heat, or shock. Mimetic word.

立たち上あがったらクラッとして、壁かべに手てをついた。
When I stood up, I felt dizzy and put my hand on the wall.
暑

あつ

さ

で

クラッ

と

き

た

の

で

、

日ひ

陰かげ

で

休やす

ん

だ

。

I felt dizzy from the heat, so I rested in the shade.

クラクラ
クラクラ describes a continuous or repeated dizzy sensation, while クラッと is a momentary, sudden dizziness.
めまい
めまい is a noun for dizziness or vertigo, often used in medical contexts. クラッと is a mimetic adverb for a sudden dizzy spell.

Mimetic word derived from the sound or sensation of sudden dizziness. The exact origin is uncertain.