Do economic dictionaries distinguish between different interpretations of terms in different economic schools of thought, or are there different dictionaries for different schools of thought?
For most part different 'schools of thought' do not have different definitions of terms. New Keynesian definition of GDP is the same as Keynesian definition of GDP or Neoclassical definition of GDP or any other 'school of thought' that you can think of. Marginal utility also has the same definition across economics. This is because terminology is not about interpretation but about definitions and most of the time it makes sense for people to agree on one definition so everyone can understand each other.
This is because in a modern context distinguishing among schools is much less useful than in past (save for classification) since nowadays any idea that can get empirical support will eventually be accepted. For example, it is no longer even valid to say that modern mainstream is just neoclassical synthesis (neoclassical economics + New Keynesian economics) since now it comprises of behavioral economics, institutional economics etc. In fact even historically mainstream economics always absorbed ideas from everywhere (you will find Austrian influences in theories on prices, Marx is why we use $K$ for capital etc.) although less so than in the present.
When terms have different definitions it is usually not across 'schools of thought' (although there might be some exceptions) but across sub-fields. For example, the definition of technology is more narrow in the growth theory than in microeconomics.
Good economic dictionaries are:
- The New Palgrave Dictionary of Economics (this is probably the most comprehensive one)
- The Economist: Economics A-Z
- Oxford A Dictionary of Economics
The above provide reasonably well overview of definitions used in economics. Most textbooks, especially undergraduate ones, will have 'glossary' at the end where you can find terminology as well.