noun
Refers to someone who actively puts a theory, skill, or discipline into practice, rather than merely studying it. Often used in professional, medical, or martial contexts.
彼は理論だけでなく、優れた実践者でもある。
He is not just a theorist but also an excellent practitioner.
この治療法は多くの実践者によって支持されている
This treatment method is supported by many practitioners.
理論家 is a 'theorist', someone who focuses on theory, often contrasted with 実践者.
Compound of 実践 (practice, implementation) and 者 (person). The spelling 實踐者 is the kyūjitai form.