The term 'alterable' is an adjective that describes something that can be changed or adapted. It is often used to describe objects, situations, or ideas that can be modified in some way. The crossword solutions for this term are CONVERTIBLE (11 letters), CHANGEABLE (10 letters), ADJUSTABLE (10 letters), and ADAPTABLE (9 letters). All of these words refer to the ability to alter something, either physically or mentally. CONVERTIBLE, for example, refers to something that can be changed from one form to another, such as a CONVERTIBLE car that can be changed from a coupe to a roadster. CHANGEABLE implies that something can be altered in some way, such as a CHANGEABLE weather pattern. ADJUSTABLE means that something can be adjusted to fit different needs or requirements, such as an ADJUSTABLE bed. Finally, ADAPTABLE means that something can be adapted to different conditions or environments, such as an ADAPTABLE plant species.