盟 is a Chinese hanzi, listed here under the keyword “swear”. It is built from 明 (bright) and 皿 (shallow container). It appears as a component in 1 other character in this index.
On KumiJi Glyph Explorer, open the parts search and type “bright” + “shallow container”. 盟 is among the results, together with every other character containing the same shapes.
Open 盟 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.