अर्धरात्रार्धदिवसardharātrārdhadivasam. the time when day and night are half and half. i.e. equal, the equinox R.
masculine gender the time when day and night are half and half. id est equal, the equinox R.
कोशःDictionaries
Every entry for a word in Apte, Monier-Williams, Macdonell and the Dhātupāṭha, with their abbreviations spelled out, and an analysis of its forms.