The eyebrow movements are considered one of the Mukhaja, or gestures of the face according to the Nātyasāstra.
The movements are used primarily to communicate meaning in the context of gesture.
Please refer to the Shloka below for pronunciation. Please note that the separate movements of the head when put together in a Shloka form 'Sandhis', or compound words in the Sanskrit language. Words like 'ca', 'thatha', mean "and", "also". The separate words for each movement are also given below the shloka.
Utkśepa pātana brukuti ćaturam tatha
kuñćita rećita sahaja ćeti saptadha