Final answer:
The creation of a new word by combining two free morphemes is known as a compound word. Examples include 'blackbird' and 'dogcatcher', where two free-standing words are joined to create a new term.
Step-by-step explanation:
The creation of a new word by combining two free morphemes is called a compound word. This linguistic process involves taking full words (free morphemes) that can stand alone with distinct meaning and joining them to create a new word. An example would be the word 'blackbird,' which is the combination of 'black' and 'bird'.
Compound words can be formed when two free stems are combined, as in 'dogcatcher' (dog + catcher) or when the joining results in a double consonant, such as 'cattail' (cat + tail) due to simple addition. This is a part of English grammar referred to as morphology, which is the study of how words are structured and formed.