Meaning : (biology) the structural adaptation of some body part for a particular function.
Example :
Cell differentiation in the developing embryo.
Synonyms : differentiation, specialization
Meaning : The act of specializing. Making something suitable for a special purpose.
Synonyms : specialization
Meaning : The special line of work you have adopted as your career.
Example :
His specialization is gastroenterology.
Synonyms : specialism, speciality, specialization, specialty