Interfix

Interfix, or, more commonly, linking element, is a term in linguistics and more specifically, phonology. It describes a phoneme which is placed in between two morphemes and does not have a semantic meaning.

Examples

Formation of compound words

In German, the interfix -s- has to be used between certain nouns in compound words, but not all, such as Arbeitszimmer ("workroom") as opposed to Schlafzimmer ("bedroom"). This originates from the masculine and neuter genitive singular suffix -s. German has many other interfixes, for example -es, -(e)n-, -er- and -e-. Not all of them originate from the genitive. Likewise, it is often stated that German interfixes originated from plural forms, when in fact German plural forms and linking forms developed parallel to each other and are only partly similar by coincidence.

In English, when technical compound words are formed from non-technical roots, an -o- interfix is sometimes used, as o has come to be seen as a connecting vowel (speed-o-meter, mile-o-meter) by analogy to tacho-meter, odo-meter, compounds of which the first part comes from an Ancient Greek noun whose stem includes o.