In linguistics, and particularly in morphology, lemma refers to the canonical form of the word. This is important mainly in the highly flexible languages[?], such as Czech.
... 18 to 24, 17.6% from 25 to 44, 20.5% from 45 to 64, and 14.1% who are 65 years of age or older. The median age is 28 years. For every 100 females there are 82.8 males. ...