Ranks amongst the lowest pledges (5)
I believe the answer is:
pawns
'pledges' is the definition.
(I know this)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for pawns that I've seen before include "made pledges" , "Chess pieces" , "The foot-soldiers in chess" , "Minor chessmen" , "Puts into hock" .)