Japanese noun for "sister".
-san being a touch of respect.
-chan for cute
nee-chan is cute @_@
by NiZ December 15, 2003
Casual Japanese noun meaning Older Sister. Onee-san is the formal form of this noun.

Onee and Onii (Older Brother) do not have to have the ending -san, -kun, -chan, or -sama
See Nii-San; Onii-san; Ototo-kun; Imoto-chan
Nee-san, when are we going to the mall?

姉、私たちがいつモール街に行きます

Onee-san, watashitachi gaitsu mo^ru machi ni iki masu?
by Khana Hatake January 1, 2010
Nee-San (Pronunciation-Nè Sa)

Meaning-Big Sister

Also:-Nee Chan is generally regarded formal for Elder sister.
by AlXN January 28, 2017