libstemmer0d binary package in Ubuntu Focal amd64

 Snowball provides access to efficient algorithms for calculating a
 "stemmed" form of a word. This is a form with most of the common
 morphological endings removed; hopefully representing a common
 linguistic base form. This is most useful in building search engines
 and information retrieval software; for example, a search with stemming
 enabled should be able to find a document containing "cycling" given the
 query "cycles".
 .
 Snowball provides algorithms for several (mainly European) languages.
 It also provides access to the classic Porter stemming algorithm for
 English: although this has been superseded by an improved algorithm, the
 original algorithm may be of interest to information retrieval
 researchers wishing to reproduce results of earlier experiments.

Source package