crawler

noun

1. A child who is able to creep using its hands and knees but is not able to walk.
2. A crawl swimmer.
3. A tractor crawler, a motorized vehicle that uses caterpillar tracks instead of wheels.
4. (Internet)A software bot that autonomously follows connected paths such as links between web pages.

   “Crawler-based search engines have three major elements. The first is the spider, also called the crawler, which visits a web page, reads it, and then follows links to other pages within the site.”

   “These serve as an algorithmic way to judge the “mobileness” of a site, and similar algorithms are likely to be used by the search crawlers.”

5. A mobile stage in the development of stationary hemipteran insects such as scale insects—generally the first instar.
6. (UK, obsolete, slang)A cab that is driven slowly along while its driver looks out for a fare.
7. Synonym of crawler crane.
8. (Australia, obsolete)A person who is abused, physically or verbally, and returns to the abuser a supplicant.
9. (Australia, UK, slang)A sycophant.