Does it even make sense to attempt to define the concept, as it would arguably require to take a view point "outside of it"?
This is from wikipedia's "defintion" of Consciousness:
Consciousness, at its simplest, is "sentience or awareness of internal and external existence". Despite millennia of analyses, definitions, explanations and debates by philosophers and scientists, consciousness remains puzzling and controversial, being "at once the most familiar and most mysterious aspect of our lives". Perhaps the only widely agreed notion about the topic is the intuition that it exists. Opinions differ about what exactly needs to be studied and explained as consciousness.
From an idealist or Cartesian dualist POV, you're almost right consciousness is like a philosophical ecstasy and actually should be avoided to try to be seriously defined and reduced further since it would arguably require to take a more fundamental substance "outside of it" while an idealist or a Cartesian dualist should not do that.
From a physicalist or functionalist POV, one may further define consciousness. A physicalist who subscribes to Behaviorism, for example, can define consciousness entirely based physical behavior of humans and other animals through scientific experiments or observations. A functionalist, on the other hand, can define consciousness as brain's functional relation between sensory inputs and behavioral outputs with multiple physical realizability by heart.
I believe that among philosophers there is a vast consensus as to the meaning of the word "consciousness" (at least as it has been used in the past three decades). But for reasons closely related to why the "hard problem of consciousness" is hard, the word "consciousness" is apparently impossible to define in words.
The best that can be done is to provide synonyms for it (like sentience), or examples of it (seeing the color red, smelling a rose).