A Lexical Chunk is a unit of language which is made up of two or more words.
Here are a few examples of lexical chunks :
Nice to see you!
What’s the time?
Other lexical chunks can include phrasal verbs, idioms, collocations and so on.
Lexical chunks are the common coinage of English. They’re the bread and butter, the everyday and the mundane. They’re the reliable standards around which we can hang poetic and emotive language.