a Japanese word , derived from a Sanskrit word 'Dhyana' which means meditation

Zen is a Japanese word , derived from a Sanskrit word 'Dhyana' which means meditation.

a practice that was uninterruptedly transmitted from master to disciple

Zen is, first and foremost, a practice that was uninterruptedly transmitted from master to disciple, and that goes back to the spiritual Enlightenment of a man named Siddhārtha Gautama (Shakyamuni Gotama in Japanese) -

a form of Mahāyāna Buddhism that stresses the practice of meditation as the key to enlightenment

Zen (禅), Japanese for "meditation," is a form of Mahāyāna Buddhism that stresses the practice of meditation as the key to enlightenment.

the practice of mindfulness meditation

Zen is the practice of mindfulness meditation (while walking, standing, laying, and sitting).

the way of meditation as the Japanese term ‘zen’ is a corruption of the Sanskrit dhyan(meditation), which was called chan in China

Zen is the way of meditation as the Japanese term ‘zen’ is a corruption of the Sanskrit dhyan(meditation), which was called chan in China.

the “meditation sect” of Buddhism

Zen is the “meditation sect” of Buddhism.

a whole philosophy on meditation

Zen is a whole philosophy on meditation, to calm the mind.

the short title for 'Meditation Buddhism' or 'Zen Buddhism' in Japan

Zen means meditation, and is the short title for 'Meditation Buddhism' or 'Zen Buddhism' in Japan.