Priming is used in two ways in EFL. Firstly it is used in Task Based Learning (notably by Jane and Dave Willis - see the articles referred to below) to describe the sort of scaffolding task often used to prepare learners for a later main task - eg brainstorming ideas on a topic before reading a text on that topic.
The Lexical Approach uses the term differently, to refer to the way language may be acquired, stored and retrieved by the brain. Selivan (2018) writes
A new theory of language acquisition known as lexical priming (advanced by Professor Michael Hoey, University of Liverpool) .... argues that as we acquire new words we take a subconscious note of words that occur alongside (collocation) and of any associated grammatical patterns (colligation). Through multiple encounters with a new word, we become primed to associate it with these recurring elements. According to Hoey’s theory, our brain is like a giant corpus where each word is accompanied by mental usage notes. Language production is not a matter of simply combining words and rules but rather a retrieval of the language we are primed for, i.e. the patterns and combinations we have previously seen or heard. This accounts for why some sentences that are perfectly grammatical may not sound natural: the words in these awkward sentences do not conform to their primings.
References and Further Reading
Willis, D. (n.d) Techniques for priming and recycling
Willis, J. (n.d) From priming tasks and target tasks to lexical focus and grammar
Selivan, L. (2018) Lexical Grammar - Introduction