n. (Hira=あな) hole, opening, gap; break; cavity, concave; cave, cavern; burrow; (Vulgar Slang) ass, arse, buttock

n. (Trad=穴, Pinyin=xue2) hole, cave

n. (Simp=穴, Pinyin=xue2) hole, cave

[穴] a hole; an aperture; an opening; a perforation; a spot where influences to one's fortune converge; a region for acupuncture

bu2 ru4 hu3 xue4, yan1 de2 hu3 zi3
If you don't enter the tigers' lair, you cannot catch any cubs.
You have to take risks to be able to gain or win. Nothing ventured, nothing gained.

qian1 li3 zhi1 di1, kui4 yu2 yi3 xue2
A thousand mile long dyke may collapse because of one ant-hole.
(No further explanation)