having good grounds: well-founded rumours
WordReference Random House Learner's Dictionary of American English © 2025
well-found•ed /ˈwɛlˈfaʊndɪd/USA pronunciation
adj.
WordReference Random House Unabridged Dictionary of American English © 2025- having or based on good reasons, sound information, etc.:well-founded objections.
well-found•ed
(wel′foun′did),USA pronunciation adj.
- having a foundation in fact;
based on good reasons, information, etc.:well-founded suspicions.
- Middle English 1325–75
Collins Concise English Dictionary © HarperCollins Publishers::
'well-founded' also found in these entries (note: many are not synonyms or translations):