What is the meaning of こ?

The hiragana syllable こ (ko). Its equivalent in katakana is コ (ko). It is the tenth syllable in the gojūon order; its position is か行お段 (ka-gyō o-dan, “row ka, section o”).

此: (derogatory) you

是: (humble) you

this

place

籠: basket

子: child; a diminutive noun

蚕: silkworm

粉: flour

濃: deep

小: small

木: tree, wood

Source: wiktionary.org