Dictionary Definition :
Definition[1]
:
宴坐 Also written 燕坐. 宴 (yan) means ease or comfort. To sit at ease. To sit quietly. Sitting meditation (zazen).
Definition[2]
:
Za-Zen. The term used in Zen to designate meditation.
Source
:
Geddes MacGregor, Dictionary of Religion and Philosophy, New York: Paragon House, 1989
Definition[3]
:
zazen
Japanese term meaning literally, ‘to sit in zen’. In Japanese Zen, this refers to the practice of seated meditation.
Source
:
A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)