In phenomenology (Husserl, Merleau-Ponty), the process by which past experiences and interpretations settle into background habits and assumptions that operate below conscious awareness, shaping how new experience is perceived without being actively noticed.
Sedimentation has a literal sense and a metaphorical one, and they should not be made to illuminate each other. In geology and chemistry it is the settling of suspended particles out of a fluid under gravity or centrifugal force, producing layers whose order records the sequence of deposition. In phenomenology and social theory the word is borrowed to describe how past practices, meanings and decisions settle into an unquestioned background — no longer noticed as choices, but functioning as the given ground of present activity. The metaphor carries the ideas of layering and of history becoming inert. Beyond that image the two senses have no useful relation, and the second varies by author.
Why this entry carries no source list. This lexicon cites an official primary source wherever one exists. For a concept used across several traditions at once, no such source exists: there is no body with authority over it, and a signed academic reference — the tier this lexicon would otherwise reach for — has no entry under this headword. Citing one school’s formulation would present a position as a definition. So the entry names the senses in play and the distinction between them, which is the part a reader can actually use.