What does Dharma mean today?

Dharma is a Sanskrit word, derived from the proto-Indo European root *dʰer- which means "to support" or "to hold."  Thus its basic meaning is "that to which we adhere," or "that which supports and upholds us." The term has evolved, throughout Hindu and Buddhist history, to carry a range of connotations (as listed in the Wiktionary from Wikipedia):

1. (Hinduism, Buddhism) the principle that orders the universe; one's conduct in conformity with such a principle
2. (Hinduism) one's obligation in respect to one's position in society
3. (Buddhism) the teachings of the Buddha as one's personal path to enlightenment [quotations ▼]
   • "Dharma practice in the tradition of the Theravada Buddhist masters enabled me to quit smoking and improve my relationships, oh, and by the way, to achieve nirvana."
4. (Buddhism) the teachings of the Buddha as a practice to be promulgated and taught.

For my own practical purposes, then, Dharma comprises these distinct but interrelated meanings for us today:

1. Phenomenon or manifestation (usually used in the plural) as in "all dharmas are empty" (of separate existence)--a core teaching of Buddhism; by this definition, everything we see is a dharma. Or putting it more simply, a dharma is a thing.
2. Calling or Vocation--an individual's Dharma refers to the specific role in life which is ideally suited to that person's temperament, talents, and aspirations. Hence my Dharma is to teach English and Humanities; my wife's Dharma is to paint pictures and create artworks. To cite a useful term from African-American dialect, then, a dharma is your "thang."
3. The Sacred Truth, intuitively perceived--that which every sacred tradition on the planet has in common, understood (as the Dalai Lama has said) as a Principle, a Precept, and a Practice simultaneously. In short, the Dharma is "the thing itself," that which upholds us, that to which we adhere.  Here is my own favorite formulation of Dharma:
• Principle: "We are caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly, affects all indirectly." --Martin Luther King, Jr. This is a succinct formulation of the Dharma as the abiding truth of the universe--combining impermanence, interbeing, and Oneness in one choice quote.
• Precept: "Take care of everyone, and abandon no one. Take care of everything, and abandon nothing."--Lao Tzu. This is the core ethical obligation--universal compassion--that follows directly from a clear understanding of the above Principle.
• Practice: "Breathe, Observe, Let Go."--The Buddha. This is the core injunction of Dharma Practice--the essential discipline taught by the Buddha and all other spiritual teachers, for letting go of ego-fixation and awakening to our essential Oneness with all life, all existence.