geminate in WordNet English dictionary

1. a doubled or long consonant
   "the `n' in `thinness' is a geminate"
   geminate 
   

1. arrange or combine in pairs
   "The consonants are geminated in these words"
   geminate 
   
2. arrange in pairs
   "Pair these numbers"
   pair  geminate 
   
3. occur in pairs
   pair  geminate 
   
4. form by reduplication
   "The consonant reduplicates after a short vowel"; "The morpheme can be reduplicated to emphasize the meaning of the word"
   reduplicate  geminate