geminate [Lat. geminata ‘doubled’] (also double consonant, long consonant)

Consonant that is distinguished from another exclusively by its longer period of articulation ( quantity). The difference between simple and long consonants is phonologically relevant in some languages, e.g. in Ital. fato (‘fate’) and fatto (‘done’), but not in others, e.g. English, where double consonant characters/letters serve only orthographically to indicate a preceding short vowel: redden.