also: シエシエ · シェイシェイ
interjection
Casual Chinese-derived expression of gratitude, used in Japanese contexts with a playful or informal tone.
from Chinese xièxie
プレゼントをもらって、「謝謝！」と言った。
Receiving a present, I said, "Xièxie!"
Alternate kanji form using 々; less common.
Katakana variant with エ instead of ェ.
Katakana variant with long vowels.
Standard Japanese thank you; 謝謝 is a Chinese loan used casually or playfully.
Borrowed from Mandarin Chinese 謝謝 (xièxie), meaning 'thank you'.