度ど胸きょうが据すわる

Meanings

1

expression, godan verb (-ru)

have steady nerves; be brave; be confident

Describes a state where one's courage is firmly settled, often used when facing a challenge or danger without flinching.

きょう

が

据す

わっ

て

いる

選せん

手しゅ

は

強つよ

い

。

A player who is confident even on the big stage is strong.

度ど胸きょうが据すわる
Standard kanji spelling using 据わる.
度ど胸きょうがすわる
Kana spelling of the verb part; common in everyday writing.
度ど胸きょうが座すわる
irregular kanji usage
Irregular kanji usage; 座る is not standard for this meaning.

度ど胸きょう
度胸 is the noun 'courage' or 'nerve'; 度胸が据わる is the verb phrase meaning 'to have that courage firmly in place'.
肝きもが据すわる
Similar meaning, but 肝 (liver/guts) is more visceral and slightly rougher in tone than 度胸.

度胸 (courage) + が + 据わる (to be set firmly). The verb 据わる implies something is settled and immovable, giving the image of courage that does not waver.