This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Having the same or a similar meaning: synonymous words.

adj. Equivalent in connotation: "a widespread impression that . . . Hollywood was synonymous with immorality” ( Doris Kearns Goodwin).

adj. having a similar meaning

adj. of, or being a synonym

adj. Such that both its forms yield the same sequenced protein.

adj. Having the character of a synonym; expressing the same thing; conveying the same, or approximately the same, idea.

Having the character of a synonym; expressing the same idea; equivalent in meaning.

adj. (of words) meaning the same or nearly the same

"It's a label synonymous with everything posh: flawless fabric, a historic design archive and top-drawer clients."

substitutable    similar   

nonsynonymous    antonymous   

synonymous relates   

synonym    synonymity   

interchangeable    identical   

anonymous    autonomous   

nonexistent    incompatible    coincident    analogous    indistinguishable    valueless    negligible    inaccessible    inseparable    unheard