Sign of life in leguminous plants (5)
I believe the answer is:
pulse
'sign of life' is the definition.
(a person's pulse)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pulse that I've seen before include "Beat or throb of heart" , "Beat; bean" , "beats reading!" , "Musical rhythm" , "Vitality" .)