An ELT Glossary : Polywords

• Definition : A type of lexical chunk. Fixed expressions made up of more than one word, but which have to be understood as a single unit meaning one specific thing, which may not be retrievable by analysing their individual parts.

• Examples : of course / by the way /  by dint of / in spite of / So long

• The fact that they need to be understood as a single unit is demonstrated by the fact that they will often (though not always) have synonymous one word equivalents - eg of course/naturally; in spite of/despite; by the way/incidentally; So long /Goodbye

• The term was first introduced by Michael Lewis in "The Lexical Approach".