Gemination n. : A doubling; duplication; repetition.

Example:
8 or 9th grade level science project on plants,seed Gemination, or soil?

Taxonomy
consonant length, consonant, Gemination, languages, long consonants, taka, vowel length, stops, initial consonant, free encyclopedia, Hungarian, Greek, phonemic, Estonian, Russian, takka, distinction, African languages.

Defination from the web:
gemination happens when a spoken consonant is pronounced for an audibly longer period of time than a short consonant. ... Phonetic gemination occurs marginally. However, gemination does occur across words when the last consonant in a given word and the first consonant ...