A lexical set is a group of words with the same topic, function or form.
'Cat, dog, tortoise, goldfish, gerbil' is part of the topical lexical set pets, and 'quickly, happily, completely, dramatically, angrily' is part of the syntactic lexical set adverbs.
In the classroom
Lexical sets are a way of looking at new vocabulary that some learners find useful. Activities include asking learners to sort words into groups, word games such as the chaining game 'I went to the market and bought…', Odd One Out, and Stop, and class poster projects.