Where does “英数字” come from?

英数字 (Japanese) comes from Japanese 英字, from Japanese 字, from Middle Chinese 字 — letter, symbol, character; character.

英数字 (Japanese): alphanumeric characters, alphanumerics

Definitions

  1. alphanumeric characters, alphanumerics

Ancestry of “英数字”, step by step

StepLanguageWordMeaning
1Japanese英字the English alphabet; a letter of the English...
2Japanese字letter, character; handwriting, penmanship; a...
3Middle Chinese字letter, symbol, character; character
Every word from Middle Chinese 字 →Every word from Japanese 字 →Every word from Japanese 英字 →