Radical 76
Radical 76 or radical lack meaning "owe", "", or "yawn" is one of the 34 Kangxi radicals composed of 4 strokes.
In the Kangxi Dictionary, there are 235 characters to be found under this radical.
欠 is also the 90th indexing component in the Table of Indexing Chinese Character Components predominantly adopted by Simplified Chinese dictionaries published in mainland China.