Gemination, or consonant elongation, is the pronouncing in phonetics of a spoken consonant for an audibly longer period of time than that of a short consonant. It is distinct from stress and may appear independently of it. Gemination literally means "twinning" and comes from the same Latin root as "Gemini".
Consonant length is distinctive in some languages, like Arabic, Berber, Maltese, Catalan, Danish, Estonian, Finnish, Classical Hebrew, Hungarian, Italian, Japanese, Latin, Malayalam, Marathi, Tamil and Telugu. Most languages (including English) do not have distinctive long consonants, however.
Vowel length is distinctive in more languages than consonant length is. Several languages, like Arabic, Japanese, Finnish and Estonian, feature both independently, however; others, like Norwegian and Swedish, have interdependent vowel and consonant length.
Lengthened fricatives, nasals, laterals, approximants and trills are simply prolonged. In lengthened stops, the obstruction of the airway is prolonged, which delays release, and the "hold" is lengthened.