サイ, ほそ.い, ほそ.る, こま.か, こま.かい

dainty, get thin, taper, slender, narrow

JLPT2 G2 S11 F537

Variant form of fine cloth → *fine*; *slight*; *thin*; *slender*; *narrow* → *detailed*; *dwindle*.

[Full Kanji Etymology List]