crawler

Short definition from Wiktionary

Noun

1. 1
   A child who is able to creep using its hands and knees but is not able to walk.
2. 2
   A crawl swimmer.
3. 3
   A tractor crawler, a motorized vehicle that uses caterpillar tracks instead of wheels.
4. 4
   A software bot that autonomously follows connected paths such as links between web pages.
5. 5
   A mobile stage in the development of stationary hemipteran insects such as scale insects—generally the first instar.
6. 6
   A cab that is driven slowly along while its driver looks out for a fare.
7. 7
   Synonym of crawler crane.
8. 8
   A person who is abused, physically or verbally, and returns to the abuser a supplicant.
9. 9
   A sycophant.