Definitions:
move forward on the hands and knees or by dragging the body close to the ground

behave obsequiously or ingratiatingly in the hope of gaining someone's favour

be covered or crowded with (insects or people), to an extent that is objectionable

(of a program) systematically visit (a number of web pages) in order to create an index of data

an act of moving on one's hands and knees or dragging one's body along the ground

a swimming stroke involving alternate overarm movements and rapid kicks of the legs