Dharm has several meanings. That which holds the Universe is Dharm. It means Natural Laws (Prakriti Dharm), justice (Nyaaya Dharm), Natural Characteristics (Swabhaav Dharm), different species (Jaati Dharm), Social Conduct (Samaaj Dharm), Religious Conduct (Shraut Dharm), Vaidik Varnaashram Dharm, Paarmaarthik Dharm, Aachaar Dharm, Neeti Dharm, Pravritti Dharm, Nivritti Dharm etc.

Whatever is the cause of prosperity and salvation is Dharm.

Laws of nature which behold all creations is called Dharm.

Dharm bestows perennial happiness and A-Dharm produces sorrow and misery.

That which is eternal is Dharm. Only God is eternal.

"That which takes us from the world to Moksh is Dharm."
--Vinoba Bhave.

"That which makes you forget yourself is Dharm".
--Masti Venkatesha Iyengar

"If you protect Dharm, it protects you."
--Bhaas

"Dharm is in action, not in blind belief."
--Dr Radhakrishnan

"Good of every one is Dharm."
--Shankaraachaarya

"Dharm is self sustaining."
--Madhwaachaarya

"Service for others is Dharm."
--Vivekananda

"Truth, non stealing, conquering anger, feeling sorry for mistakes committed, cleanliness, firm mind, discrimination between good and bad, absence of haughtiness, control of senses and good education are the essential parts of Dharm.
--Yaagyavalkya

The wise should practice Dharm alone, it takes a man to next stage. The study of Poorv Meemaansaa and Karm Kaand in Ved are useful for this purpose.