无定形碳 wúdìngxíngtàn amorphous carbon Origin Definitions Defs Strokes Stroke Words Sentences Sents 无定形 無定形 wúdìngxíng amorphous having no definite form or structure; formless碳 tàn noun carbon nonmetallic element (C); the essential component of organic matter, existing in nature as diamond, graphite, and coal