crawler

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One that crawls, especially an early form of certain insect larvae.
2. n. A vehicle, such as a bulldozer, that moves on continuous belts of metal plates.

Century Dictionary and Cyclopedia

1. n. One who or that which crawls; a creeper; a reptile.
2. n. A dobson or hellgrammite; the larva of a neuropterous insect of the family Sialidæ, as of Corydalus cornutus.
3. n. Also called clipper.
4. n. A person or thing that moves slowly; particularly, a cab that moves along a street very slowly on the outlook for a fare.

Wiktionary

1. n. A child who is able to creep using his hands and knees but is not able to walk.
2. n. A crawl swimmer.
3. n. A tractor crawler, a motorized vehicle that uses caterpillar tracks instead of wheels to achieve superior floatation and traction. Crawlers are more expensive in maintenance and harder to operate than wheel tractors, but are often critical for working on soft soils, transporting great weights, and especially for bulldozing.
4. n. A software bot that autonomously follows connected paths such as webpage links.
5. n. A sycophant
6. n. A person who is abused, physically or verbally, and returns to the abuser a supplicant.

GNU Webster's 1913

1. n. One who, or that which, crawls; a creeper; a reptile.

WordNet 3.0

1. n. a person who tries to please someone in order to gain a personal advantage
2. n. a person who crawls or creeps along the ground
3. n. terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers