First, as for the meaning of Dharma, in general, the word for Dharma in Tibetan, Chö, has many meanings, but in this context, it is that which guides your mind in a positive direction, a good path; that which transforms your mind into an antidote to delusion.  The word, Dharma, is Sanskrit.  Dharma means to hold or to protect.  It holds our body, speech, and mind from falling over the cliff of the delusions, misdeeds, and so forth, and protects us from hindrances on our path to Liberation.  The Tibetan translators, however, in order to make it easy to understand, translated it simply as Chö. Chö means to transform.  What do we need to transform?  Our body, speech, and mind.

Buddha said:

Commit no misdeed whatsoever.
Practice the perfection of virtue.
Bring your mind fully under control.
This is the teaching of the Buddha.

Many people think, I’m just fine, I don’t need to change.  As long as we are someone wandering in samsara, however, none of us are completely faultless; and we all definitely need change and transformation in our lives.

Written by Khenpo Karten Rinpoche, in his book Precious Teachings, the chapter “Purpose and Benefits of the Holy Dharma,” page 86 in the paper book, and page 93 in the online pdf.