郑 is a simplified Chinese hanzi, listed here under the keyword “state in today's henan”. It is built from 关 (frontier pass) and 阝 (place). It appears as a component in 2 other characters in this index.
On KumiJi Glyph Explorer, open the parts search and type “frontier pass” + “place”. 郑 is among the results, together with every other character containing the same shapes.
Open 郑 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.