Definition of lemmatize in US English:

lemmatize

verb

[with object]
  • Sort words by grouping inflected or variant forms of the same word.

    • ‘The vocabulary lists were next lemmatized by hand.’
    • ‘Every word of these texts is tagged, lemmatized, and hypertext-linked to the Liddell-Scott (an abridged version), Louw-Nida, Friberg, Thayer, or Barclay-Newman lexicons.’

Pronunciation

lemmatize

/ˈleməˌtīz//ˈlɛməˌtaɪz/