Tonic adjectives are listed in this post. Each word below can often be found in front of the noun tonic in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing TONIC.
best, bitter
excellent, general
good, mental
moral, powerful
wholesome, wonderful
Hope this word list had the adjective used with tonic you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.
Please add more adjectives to make this list more complete: