What is the term for the beginning sound in a word?

The term for the beginning sound in a word is referred to as the onset. In phonological awareness, the onset is the initial consonant or consonant cluster of a syllable. For example, in the word “cat,” the onset is the /k/ sound. Recognizing the onset is crucial for developing reading skills, as it helps children decode and pronounce words by identifying their initial sounds.

A rime, in contrast, consists of the vowel and any following consonants in the syllable, such as the -at in "cat." Phoneme is a more general term for the smallest unit of sound in a language, not limited to just the beginning sound. A blend refers to two or more consonants that are pronounced together, but each consonant retains its sound, such as in "splash." Therefore, the correct term for the beginning sound in a word is indeed the onset.