Small unit of matter (4)
I believe the answer is:
atom
(Other definitions for atom that I've seen before include "Moat (anag.)" , "Nucleus surrounded" , "Particle; molecule" , "A wee bit" , "tiny thing" .)
I believe the answer is:
atom
(Other definitions for atom that I've seen before include "Moat (anag.)" , "Nucleus surrounded" , "Particle; molecule" , "A wee bit" , "tiny thing" .)