A tat-puruṣa compound ending with the word chāyā 'shadow' in neuter in gender when the sense is that of profuseness of the thing indicated by the first term.,
Thus, शलभछायम् 'A crowd of locusts darkening the sky.' इक्षुछायम् 'the sugarcane shade i. e., groves of sugarcane,' Otherwise, कुड्यच्छाया 'the shadow of a wall.' 6.2.14, accent.)
The sutra (2. 4. 25) gives optional neuter; this rule enjoins invariable neuter when chhaya has the sense of profuseness.,