This is the 262nd most frequent German word.
neuer
"Neuer" means "newer" or "more recent" in English.
In this sentence, 'neuen' is an inflected form of 'neu', agreeing with the masculine singular noun 'Tisch' in the accusative case.
Ich habe einen neuen Tisch gekauft.
I bought a new table.
Here, 'neu' is used in its feminine singular form 'neue', agreeing with the feminine noun 'Idee' in the nominative case.
Eine neue Idee kam mir in den Sinn.
A new idea came to my mind.
In this example, 'neuen' is the plural form of 'neu', agreeing with the plural noun 'Regeln' in the nominative case.