In linguistics, pre-stopping, also known as pre-occlusion or pre-plosion, is a phonological process involving the historical or allophonic insertion of a very short stop consonant before a sonorant, such as a short [d] before a nasal [n] or a lateral [l], or a short [p] before a nasal [m]. The resulting sounds ([ᵈn, ᵈl, ᵖm]) are called pre-stopped consonants, or sometimes pre-ploded or (in Celtic linguistics) pre-occluded consonants, although technically [n] may be considered an occlusive/stop without the pre-occlusion.
A pre-stopped consonant behaves phonologically as a single consonant. That is, like affricates and trilled affricates, the reasons for considering these sequences to be single consonants lies primarily in their behavior.[1] Phonetically they are similar or equivalent to stops with a nasal or lateral release.