Crawl abjectly (6)
I believe the answer is:
grovel
'crawl abjectly' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for grovel that I've seen before include "Cringe in abject manner" , "Cringe, be obsequious" , "Cower, abase oneself" , "Crawl abjectly" , "Humble oneself in supplication" .)