Which term describes a consonant produced by the rapid contact between two speech organs?

The term that describes a consonant produced by the rapid contact between two speech organs is "flap." A flap, also known as a tap, occurs when a speech organ, such as the tongue, makes a quick and light contact with another structure in the vocal tract, which often results in a brief sound. This can be observed in many languages, particularly in American English, where the /t/ sound in "water" or the /d/ sound in "butter" can be pronounced as a flap, resulting in a sound that resembles a quick, bouncing gesture rather than a full closure.

The other terms do not fit this definition: "hedge" refers to a linguistic term related to the use of cautious language to lessen the impact of a statement; "morpheme" is the smallest grammatical unit in a language, dealing with meaning and structure rather than pronunciation; and "metaphor" signifies a figure of speech involving an implicit comparison between two unrelated things. Each of these terms pertain to different aspects of language, focusing more on semantics or syntax rather than phonetics, which is where flaps are categorized.