1. 溶蚀残丘：hayesine 硼酸方解石 | haystack 溶蚀残丘 | head amplifier 前置放大器

2. 桂林山;石灰岩残丘：鬼里螺;骨螺 Murex | 桂林山;石灰岩残丘 haystack | 桂林山灰岩残丘 hum

3. 干草堆 (名)：hayseed 干草种子; 乡巴佬; 干草屑 (名) | haystack 干草堆 (名) | haywire 混乱的; 疯狂的 (形)

1. （露天）干草堆，干草垛
A haystack is a large, solid pile of hay, often covered with a straw roof to protect it, which is left in the field until it is needed.

2. 落进干草垛里的一根针（比喻如大海捞针般难找的东西）
If you are trying to find something and say that it is like looking for a needle in a haystack, you mean that you are very unlikely indeed to find it.

noun

1. a stack of hay

Synonym: hayrickrick