Depending on how it's wielded at times, "objective" may be corrupted by background metaphysics and theories slash philosophies like direct perception and direct realism. In those cases, a situation we might crudely compare to a discussion about planetary origins taking place, but wherein the terms available all stem from a creationist school of thought. (Which is to say, the very units of parlance for such a conversation would be loaded beforehand with an underlying bias.)
To avoid metaphysics and accompanying dogma, "objective" can be conceived as the commonality of what the majority of people experience -- those that set standards based on what they have consensus about. And darn the social justice outcries over the excluded minority that's suffering from clinical conditions (who represent the world differently as well as contingently lack sight, hearing, pain, etc).
For instance, the definitions below draw from the content of senses. Not inference or apprehension via reason of an otherwise "not manifesting to itself" version of existence (like a physical universe or an immaterial one of abstract ideas rather than phenomenal events). Yes, the brain apparatus outputting our experiences is actually engaging in degrees of vetted guesswork itself -- but that's at least innate, evolutionary preferences rather than the later socially and personally acquired tendencies concerning understanding of what one sees, hears, smells, etc.
What's key is that biological processes do manage to install the same "operating system" for sensation/experience in most of the species, sans the wayward "defects" and mutational strayings in the lesser number of individuals. Making consensus possible (in the majority population). Few will declare an oncoming train to be an illusion if most of the crowd perceives it. Even a "hip" leftangelical critic of the West -- who might pretentiously be contending that their subculture doesn't accept the reality of trains -- will eventually abandon flirtation with suicide by stepping off the tracks.
Adjective: objective ub'jek-tiv or ób'jek-tiv
Undistorted by emotion or personal bias; based on observable phenomena
"an objective appraisal"; "objective evidence";
- nonsubjective
Emphasizing or expressing things as perceived without distortion of personal feelings or interpretation
"objective art"
Belonging to immediate experience of actual things or events
"objective benefits"; "an objective example"; "there is no objective evidence of anything of the kind"
Consciousness is another term that's both unstable in terms of what it means and is loaded with pre-existing biases and philosophical baggage that accordingly obstructs inquiry into it (subjectivity or "mental" classification being one of those, which hampers reducing it down to an ontological attribute or capacity simply recruited by the brain for its sophisticated representations). The most unassailable version of "consciousness" simply subsumes everything happening in cognitive science and philosophy of mind -- an umbrella concept, IOW. But that generality thereby renders it useless for addressing anything specific -- and clearly some philosophers and scientists are narrowly applying it to a particular issue in the Hard Problem, not the whole herd of affairs.