Bilayers

Part of speech: noun

Definitions

1. A configuration made up of two parallel layers, commonly associated with biological membranes that delineate distinct compartments
2. An arrangement consisting of two stacked sheets, which often describes structures in biochemistry relevant to cellular membranes and separation
3. A structure composed of two adjacent layers arranged side by side, typically found in cell membranes separating internal and external environments

Etymology: The plural of "bilayer," which is built from the prefix "bi-" (two) and "layer." The prefix comes from Latin "bi-," itself descended from the same ancient root that gives "two" in many languages, and it was attached to the English noun "layer" to name a structure of two stacked sheets. The ancestry of "layer" is the more tangled part: it traces back through Middle English "leyen," Old English "leċġan" (to lay something down), and a Proto-Germanic verb meaning to cause something to lie, so a "layer" is literally one who lays things down. The compound itself is a plain modern formation, built by joining "bi-" to an existing English word rather than borrowed whole from another language. Its use in biochemistry, especially for the double sheet of lipid molecules that forms the boundary of a cell, is where the term has become most familiar.

Synonyms: double layers, laminates