Just to make it clear, this doesn't only apply to imported words (although it's probably where it's more common). It works for purely Japanese words too. For ex

Just to make it clear, this doesn't only apply to imported words (although it's probably where it's more common). It works for purely Japanese words too. For example: なるはや (naruhaya) is a 4 mora abbreviation of なるべく早く (narubeku hayaku). Another one: あけおめ (akeome) is an abbreviation of 明けましておめでとうございます (akemashite omedetougozaimasu)