ti̍t-ti̍t直直

straight as an arrow

straight as an arrow; dull; absent-minded; exactly; honestly; truthfully

ideophonicof expression in one's eyes

English Wiktionary, “直直” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E7%9B%B4%E7%9B%B4 · confidence: Medium (Wiktionary)