The word "inter-convertible" refers to the ability to be converted from one thing to another, typically referring to properties or characteristics. Some antonyms of "inter-convertible" include fixed, permanent, distinct, separate, individual, and unique. Fixed and permanent emphasize stability and unchangeability, while distinct, separate, and individual emphasize differences and uniqueness. Unique implies a one-of-a-kind quality, contrasting with inter-convertible's interchangeability. In contrast, "inter-convertible" suggests malleability and the ability to change and adapt, while its antonyms suggest rigidity and steadfastness. Overall, understanding these antonyms helps to clarify the nuances and implications of the term "inter-convertible.