Compound of shishi (“deer”) and odoshi (“threat”). shishi originally meant "beast" and included other types of animals. The device was originally used to scare away animals.
Alternative forms 
鹿威し (hiragana ししおどし, romaji shishiodoshi)
- a device used to scare away bird and animals
- a traditional device found in Japanese gardens; composed of a bamboo tube that when filled with water revolves to empty and makes a clanking sound