(mycology) A ring of fibers on the stem of a mushroom that is not well enough defined to be called an annulus.

(US, California) An area of a street where the curb has been painted white, indicating that the spot is only to be used for the immediate loading or unloading of passengers, baggage or freight, or for short-term parking, and (in some places, such as airports) that a vehicle is not to be left unattended.

An area of a street or a parking lot designated for the loading or unloading of passengers, baggage or freight, or short-term parking for that purpose.

(idiomatic) In a mental state of focused concentration on the performance of an activity, in which one dissociates oneself from distracting or irrelevant aspects of one's environment.

(geology) A deep level seismic zone on the line of subduction. This zone can be as deep as 700km.

(geology) A deep-level seismic zone on the line of subduction. This zone can be as deep as 700km.

The photic zone

(computing, informal) The rule that a database, a user interface, etc. should allow for either zero, one, or an indefinite number of an entity.

atmospheric air specially cleaned so that it contains less than 0.1 ppm of hydrocarbon impurities; it then is usable in laboratory procedures such as versions of gas chromatography in which sufficiently pure air may serve as a carrier gas.

(usually used attributively, finance) A non-existent coupon. / (finance) A financial security that does not pay interest periodically.