hairy cell leukemia a form of chronic leukemia marked by splenomegaly and by an abundance of abnormal large mononuclear cells covered by hairlike villi (hairy cells) in the bone marrow, spleen, liver, and peripheral blood.
A set of orbitals are said to be degenerate if they all have the same energy. This degeneracy can sometimes be lifted by external electric or magnetic fields.
heterocycle - a ring of atoms of more than one kind; especially a ring of carbon atoms containing at least one atom that is not carbon. heterocyclic ring. closed chain, ring - (chemistry) a chain of atoms in a molecule that forms a closed loop.