The audience fell silent at his astonishing performance.
I'm amazed at how unflappable that new employee is.
Means 'courage' or 'nerve' in a more general sense. 度肝 is more visceral and often used in the phrase 度肝を抜く.
Standard kanji spelling.
Variant using 胆 (gallbladder/liver) instead of 肝 (liver); both convey the idea of innards/guts.
Emphatic katakana ド plus 肝; the reading ドぎも is a natural voiced variant.
Compound of 度 (ど, degree/extent) and 肝 (きも, liver/guts). The reading ぎも is a voiced variant (rendaku) of きも. The word figuratively refers to one's innermost courage.