The word śīrṣan 'head', is found in chandas,
This word is another form of शिरः and means 'head'. This is not a substitute of शिर in the Vedas, for both forms are found therein. Thus शीर्ष्णा हि तत्र सोमं क्रीतं हरन्ति, यत्ते शीर्ष्णो दौर्भाग्यम् ॥ In the secular literature there is only one form शिरः ॥,