Herb died diseased (4)
I believe the answer is:
dill
'herb' is the definition.
(I know that dill is a type of herb)
'died diseased' is the wordplay.
'died' becomes 'd' (abbreviation next to the year of someone's death).
'diseased' becomes 'ill' (I am not sure about this - if you are sure you should believe this answer much more).
'd'+'ill'='DILL'
Can you help me to learn more?
(Other definitions for dill that I've seen before include "medicinal plant" , "Herb commonly used with gravlax" , "Herb for gravadlax" , "Herb with thread-like foliage used as seasoning" , "Herb used in cooking" .)