The Hebrew word so rendered means simply a round vessel or cup for containing ink, which was generally worn by writers in the girdle (Ezek. 9:2, 3, 11). The word "inkhorn" was used by the translators, because in former times in this country horns were used for containing ink.

Noah Webster's New International Dictionary of the English Language

1. (n.) A small bottle of horn or other material formerly used for holding ink; an inkstand; a portable case for writing materials.

2. (a.) Learned; pedantic; affected.