"Smell-less" is a highly specific word that refers to something that has no discernible odor. However, there are several synonyms available that can be used in its place. For instance, the word "odorless" can replace "smell-less" in most cases. It is a more general term that implies a lack of odor or smell. "Inodorous" is another synonym which can be used to mean the same thing. It originates from the Latin word "inodorus" which means "without smell". Other synonyms for "smell-less" include "scentless", "unscented", "fragrance-free" and "neutral". All these words can be used interchangeably in various contexts to convey the same meaning as "smell-less".