A little matter (4)
![Ross](/clue/static/ross-mug.min.png)
'a little matter' is the definition.
(tiny particle of matter)
This is the entire clue.
(Other definitions for atom that I've seen before include "Small amount of matter" , "An explosive particle as in bomb" , "Nucleus surrounded" , "A small but mighty particle" , "It was once thought to be smallest particle of matter" .)
This could be a double definition.
'a little' is the first definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'matter' is the second definition.
(ion is a kind of matter)
Can you help me to learn more?
(Other definitions for ion that I've seen before include "Charged atom/molecule" , "Eletrically charged particle" , "Particle (phys.)" , "Electrically charged particle" , "Electrically-charged particle" .)