The word "foul-smelling" typically refers to odors that are unpleasant, offensive, or even repulsive. However, there are several antonyms that can be used to describe pleasant smells. For instance, the word "fragrant" denotes a sweet or pleasant fragrance, while "aromatic" means having a distinctive, inviting smell. Similarly, the term "perfumed" can refer to a pleasant scent or fragrance, while "sweet" describes smells that are pleasing to the senses. Other antonyms for "foul-smelling" include "fresh," "clean," "invigorating," and "enchanting," each of which conveys a sense of cleanliness, freshness, and positivity.