Passierbar

Passierbar is a German adjective meaning "able to be passed" or "passable." It is used to describe routes, barriers, or openings that can be crossed or traversed, as well as substances or structures that permit the passage of something. In everyday language it often refers to roads, gates, or terrain: for example a passierbare Straße or a passierbare Brücke indicates that traffic can move through.

In the sciences the term is used more specifically to denote permeability or transmissibility. A membrane or barrier may be described as passierbar for water, ions, or small molecules, indicating that substances can cross it under given conditions. Similarly, in geology or hydrology, a channel or passage can be called passierbar when fluids or sediments can move through it.

Passierbar is commonly contrasted with unpassierbar (impassable) and with durchlässig (permeable, in a more general sense). The noun form is Passierbarkeit (passability), which denotes the property of being passable. In some contexts the word may be used more figuratively to indicate that a plan, route, or sequence of steps is practically achievable or not hindered by insurmountable obstacles.

Examples: Die Straße ist passierbar nach dem Unwetter. Der Tunnel ist passierbar, sobald die Sperrung aufgehoben wird. Die Membran ist passierbar für Wasser, aber nicht für größere Moleküle. These uses reflect a neutral, descriptive tone typical of encyclopedia-style writing.