abhava: feeling of non-being, absence of awareness pratyaya: going toward conviction, trust alambana: support, abode, dependence on a prop vrttih: function, condition, thought-wave nidra: sleep without dreams Sleep is the non-deliberate absence of thought-waves or knowledge. In a dreamless sleep the consciousness is stilled without any effort.  

sabdajnana: verbal knowledge anupati: followed in sequence, pursued vastusunyah: devoid of meaning vikalpah: imagination Verbal knowledge devoid of substance is fancy or imagination. Having an imagination is helpful (and fun) but we cannot live in this realm all the time. At some point the imaginary words or thoughts can become an untruth.