Scrabble?! LEMMA

Definitions of LEMMA in various dictionaries:

noun - a subsidiary proposition that is assumed to be true in order to prove another proposition

noun - the lower and stouter of the two glumes immediately enclosing the floret in most Gramineae

noun - the heading that indicates the subject of an annotation or a literary composition or a dictionary entry

A subsidiary proposition assumed to be valid and used to demonstrate a principal proposition.

A theme, an argument, or a subject indicated in a title.

A word or phrase treated in a glossary or similar listing.

The outer or lower of the two bracts that enclose the flower in a grass spikelet.

noun - a type of proposition in logic