crawler

noun

• 1a thing that crawls or moves at a slow pace, especially an insect: the light bulb was a magnet for moths and many-legged crawlers
• a tractor or other vehicle moving on an endless caterpillar track: the crawlers move space shuttles to the launch pads [as modifier]:a crawler excavator
• Computing a program that searches the Internet in order to create an index of data.

• 2British informal a person who behaves obsequiously in the hope of gaining favour: her pleading tone surprised herself, she was no crawler