The term lay refers to common, or non-specific terminology, in the way that a lay person is a person not a member of the clergy - or, a common person, not ordained. Common terminology would, therefore, be terms used in everyday language, and those can be taught and introduced to students in much the way that any other vocabulary terms would be presented. This is commonly done with English-as-a-second-language learners, who do not know "common" vocabulary. Using real objects and using lots of graphics, or pictures, is one strategy. One other learning ...
The solution discusses learning common vocabulary in the English as a second language class.