Number & MeasureGreek → English
Lemma
/ˈlɛmə/noun
A subsidiary proposition proved on the way to a main theorem.
The Greek roots
λῆμμα
lêmma
thing taken, premise
Literally: “something taken”
Follow a root:λῆμμα3 words
The story of the word
From lambanein, to take: a lemma is a thing you take as given, or take up in passing. Greek geometers used it for a helping result proved separately so the main proof would not sag under it. The plural is lemmata, and dilemma is literally two premises, both of them unwelcome. Lexicographers use lemma differently again, for the headword under which a dictionary files a word.
- How it travelled
- Ancient Greek → Latin → English
- First recorded
- 16th century
The same roots elsewhere
Other languages reached for exactly the same Greek pieces.
Same family
dilemmaepilepsysyllableanalemma
In a sentence
The whole proof rests on a lemma that takes half a page.