吁 is a simplified Chinese hanzi, listed here under the keyword “interjection 'alas!'”. It is built from 口 (mouth) and 于 (in). It appears as a component in 1 other character in this index.
On KumiJi Glyph Explorer, open the parts search and type “mouth” + “in”. 吁 is among the results, together with every other character containing the same shapes.
Open 吁 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.