Lemmatization

Image created with Wordle.

Lemmatization is the process through which lexicographers assign word forms to a certain headword. For example, Modern English word forms such as burn, burns, burning, and burned all belong to the word to burn.

Old English is an inflected language.  Its words change substantially by tense, number, or case.  Its spelling is not standardized; depending on region or dialect, one word can be spelled in many different ways.  Lemmatizing words appropriately--assigning the right word forms to a headword and a definition--takes care and patience.