Obsolete form of echo.

plural of re-echo

plural of light echo

A poem constructed by the surrealist technique of alternately writing a stanza and then "mirroring" it in some fashion to create the following stanza.

(physics) A form of resonance sometimes observed as a coherent pulse of light after two similar pulses have traversed a medium.

plural of echo chamber

A room or other enclosed space that is highly conducive to the production of echoes, particularly one that has been designed and built for this purpose.

(phonology) A paragogic vowel that is a repetition of the final vowel of a word

(astronomy) A phenomenon caused by light reflected off surfaces distant from the source, and arriving at the observer with a delay relative to this distance, analogous to an echo of sound.

The technique of using reflected pulses of sound to determine depth or the location of objects (or fish) under water. / A particular measurement made using this technique.