Initial dropping is a sound change whereby the first consonants of words are dropped. Additionally, stress may shift from the first to the second syllable, and the first vowel may be shortened, reduced, or dropped, which can mean the loss of the entire first syllable of a word. These changes have occurred independently in several Australian Aboriginal language groups.

Initial dropping may affect all initial consonants, or only some or one of them. It may affect all words that start with those consonants, or sporadically affect some words and not others. In some languages, it seems to have only affected interjections, and words commonly used as vocatives such as pronouns and kin terms. Like all sound changes, it may affect an entire language or just some dialects, and may affect multiple adjacent languages or dialects.