Paramahamsa Prajnananandaji in this clip on Yoga Sutra of Patanjali gives us insight into the various meanings of viveka ...
what is viveka nithya anithya vastu viveka viveka is the ability to distinguish between real and unreal Eternal and ephemeral good and not good the power of discrimination as vyasadeva is telling satta purusa what is this knowledge of discrimination here satta means established in reality established in truth purusa the indwelling spirit the indwelling spirit is the only reality is truth other than that they are on truth unreal purusa how to cultivate this discrimination whether you follow The Path of Knowledge devotion whether you follow the path of action overall when you follow the practice of yoga you should cultivate this ability to discriminate this ability to discriminate is essential characteristic of every Seeker this discriminative cognition discriminative attitude always to think is it needed or not is it right or not it is real or unreal my real goal is this is this going really to help me or is it a distraction a true Seeker is always discriminative is it stunning as an obstacle in my way or is it helpful discrimination foreign one who distinguishes between the experiencer and the experienced viveka so I what I am experiencing it is not me what I am seeing it is not me what I am thinking it is also the function of mind it is not me it is my thought it is not me the thought so every moment to discriminate to distinguish that I am this year I am the experiencer and this is the object of experience not to be identified with all these viveka it is the ability to discriminate between purusa and prakruti it is ability to distinguish between purusa prakruti it is also the ability to distinguish between I the purusa and the body distances the mind memory ego and to distinguish that I am different from them this is viveka