The verb that helps clarify or complete the core meaning of the main verb (मुख्य क्रिया) is known as:

The verb used alongside the main lexical verb to specify its tense, aspect, or mood is called an auxiliary verb, or सहायक क्रिया (Sahayak Kriya) in Hindi. For example, in "वह पढ़ रहा है" (He is reading), 'पढ़' is the main verb, while 'रहा है' acts as the auxiliary verb to clarify the progressive tense context.