Sadarmik (or sadārmīk) in Jainism means a virtuous, righteous person who lives by true dharma or moral conduct. Key sense:

• A person who follows right conduct (non-violence, truth, non-stealing, celibacy or controlled senses, and non-attachment), and acts with compassion.
• Often used to describe someone who is diligently committed to Jain ethical ideals, whether as a householder or a seeker.
• The core idea is adherence to dharma with integrity and purity of conduct.

There isn’t a big difference in the basic meaning between Digambar and Shwetambar traditions; both use it to praise someone who upholds Jain moral principles. If you’d like, I can give a short quotable definition in Sanskrit or point to a Jain text where the term appears.