काली कराली च मनोजवा च सुलोहिता या च सुधूम्रवर्णा ।स्फुलिङ्गिनी विश्वरुची च देवी लेलायमाना इति सप्त जिह्वाः ॥ ४ ॥
In plain words
Kālī, Karālī, Manojavā, Sulohitā, Sudhūmravarṇā, Sphuliṅginī, and the all-shining Devī Viśvarucī—these are the seven flickering tongues.
The commentators
Muṇḍakopaniṣadbhāṣyam· bhāṣya
अवर्णा । स्फुलिङ्गिनी विश्वरुची च देवी लेलायमाना दह नस्य जिह्वा । काल्याद्या विश्वरुच्यन्ता लेलायमाना अग्ने र्हविराहुतिग्रसनार्था एता किल सप्त जिह्वा ॥
In plain words
Avarṇa, Sphuliṅginī, and Viśvarucī—the flickering, luminous tongue of fire. From Kālī up to Viśvarucī, these seven constantly dancing tongues of fire are indeed designed to consume the sacred oblations.
Close to the Sanskrit
Avarṇa, Sphuliṅginī, and Viśvarucī, the shining and flickering tongue of fire. Beginning with Kālī and ending with Viśvaruci, flickering, these are indeed the seven tongues of fire intended for swallowing the oblation offerings.