Collins Chinese Dictionary Plus (3rd edition), 2011:
敢
gǎnI 形
courageous
II 动
1
(=有胆量) dare
- 敢于(於) gǎnyú dare to
2
(=有把握) be sure
- 我敢断(斷)定他在撒谎(謊)。 Wǒ gǎn duàndìng tā zài sāhuǎng. I'm sure he is lying.
3
(谦) (请求) venture
- 敢问(問)姓大名? Gǎnwèn zūn xìng dà míng? May I ask your name?