synonymous

UK: /sɪˈnɒnɪməs/ US: /sɪˈnɑnəməs/ ,(si non′ə məs)

WordReference Random House Learner's Dictionary of American English © 2025

syn•on•y•mous /sɪˈnɑnəməs/  adj. 

1. of or relating to synonyms.
See syn-, -onym-.

WordReference Random House Unabridged Dictionary of American English © 2025

syn•on•y•mous  (si non′ə məs), adj. 

1. having the character of synonyms or a synonym;
   equivalent in meaning;
   expressing or implying the same idea.

• Greek synó̄nymos, equivalent. to syn- syn- + -ōnym- -onym + -os adjective, adjectival suffix; see -ous
• Medieval Latin synōnymus
• 1600–10

syn•on′y•mous•ly, adv. 
syn•on′y•mous•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

synonymous / sɪˈnɒnɪməs/ adjective

1. (often followed by with) being a synonym (of)
2. (postpositive) followed by with: closely associated (with) or suggestive (of): his name was synonymous with greed

synˈonymously adverb

synˈonymousness noun