中

chuu

Meaning:	1) while, 2) throughout
JLPT Level:	3

Examples

店は準備中なので帰りましょう。
mise wa junbi chuu na node kaerimashou.
store-(topic marker)-preparation-still continuing-therefore-return home
The store isn't open, so let's go home.

年中無休
nen juu mu kyuu
year-long-not-rest
Open year long.

Comments

1) while, during 電話中 denwa chuu - While on the phone
2) throughout 世界中 sekai juu - throughout the world; all the world (notice the sound change with juu instead of chuu)

Also see [[～ながら]]