Enlightment
"Enlightenment is a state of perfect knowledge or wisdom, combined with infinite compassion. Knowledge in this case does not mean merely the accumulation of data or a description of the world of phenomena down to the finest details. Enlightenment is an understanding of both the relative mode of existence (the way in which things appear to us) and the ultimate mode of existence (the true nature of these same appearances). This includes our own minds as well as the external world. Such knowledge is the basic antidote to ignorance and suffering.”
Source: https://www.matthieuricard.org/en/blog/posts/what-does-buddhism-mean-by-enlightenment
Mindfulness
"Mindfulness is the basic human ability to be fully present, aware of where we are and what we’re doing, and not overly reactive or overwhelmed by what’s going on around us. Mindfulness is a quality that every human being already possesses, it’s not something you have to conjure up, you just have to learn how to access it.”
Source: https://www.mindful.org/what-is-mindfulness/
Nirvana
“A transcendent state in which there is neither suffering, desire, nor sense of self, and the subject is released from the effects of karma and the cycle of death and rebirth. It represents the final goal of Buddhism.”
Source: https://www.lexico.com/definition/Nirvana
Om
"Om is a very simple sound with a complex meaning. It is the whole universe coalesced into a single word, representing the union of mind, body, and spirit that is at the heart of yoga.”
Source: https://www.verywellfit.com/the-meaning-of-om-3566806
Spirituality
"Spirituality involves the recognition of a feeling or sense or belief that there is something greater than myself, something more to being human than sensory experience, and that the greater whole of which we are part is cosmic or divine in nature.”
Source: https://www.rcpsych.ac.uk/docs/default-source/members/sigs/spirituality-spsig/what-is-spirituality-maya-spencer-x.pdf?sfvrsn=f28df052_2
Zen
"A state of meditative calm in which one uses direct, intuitive insights as a way of thinking and acting.”
Source: https://www.dictionary.com/browse/zen