Nucleus (6)
'nucleus' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for core that I've seen before include "essential element" , "Central or most important part of something" , "The centre of an object" , "The centre part, as of an apple" , "Centre, heart" .)
'nucleus' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for kernel that I've seen before include "Edible seed of nut" , "Essential part" , "Inner part of nut" , "soft heart" , "Nut's centre" .)