The term 'BIRD's Word' can be solved by two crossword solutions: CHEEP (5 letters) and TWEE (4 letters). CHEEP is a sound made by birds, usually associated with small birds such as sparrows or finches. It is also used to describe the sound of a person speaking in a high-pitched voice. TWEE is an adjective that describes something as being overly cute or sentimental. It is often used to describe things that are considered too sweet or innocent.