Final answer:
The term for two or three graphemes representing distinct phonemes in a syllable is a 'blend'. A 'digraph' is a pair of letters representing a single sound, while a 'trigraph' consists of three letters for one sound.
Step-by-step explanation:
Understanding Graphemes and Phonemes in English
The question refers to two or three graphemes each representing a distinct phoneme and forming a blend without merging into a single sound before or after a vowel in a syllable. The correct term for this is a blend.
Digraph and Trigraph
A digraph is a pair of letters representing one sound, like the long e sound in words such as 'bead' with , or 'seed' with . Similarly, a trigraph includes three letters that combine to represent a single sound.
Blend
A blend, on the other hand, consists of two or three consonants placed together where each consonant's sound is still heard. Examples of blends include 'bl' in 'black' and 'str' in 'street'.
Therefore, when two or three adjacent consonants are heard distinctly in a syllable without merging into one sound, the correct term for this concept is a blend.