a computer program that works automatically, especially one that searches for and finds information on the internet

Criminals create networks of bots that roam the internet infecting PCs with malware. 犯罪分子制造网上机器人网络，通过恶意软件感染电脑用户。

informal a robot

a person's bottom

Is Kylie's bot the greatest ever? 凯莉的屁股是史上最大吧？