RELENTLESS /ɹɪˈlɛntləs/ Scrabble 10 Words With Friends 13 Definition adjective not to be placated or appeased or moved by entreaty. — synonyms: grim, inexorable, stern, unappeasable, unforgiving, unrelenting adjective never-ceasing. — synonyms: persistent, unrelenting See all 184 words you can make from RELENTLESS → 10-letter words Words starting with R Words ending with S ← Unscramble different letters