From Longman Dictionary of Contemporary Englishforewarnfore‧warn /fɔːˈwɔːn $ fɔːrˈwɔːrn/ verb [transitive] 1 WARNto warn someone about something dangerous, unpleasant, or unexpected before it happensbe forewarned of/about something We’d been forewarned of the dangers of travelling at night.Grammar Forewarn is often used in the passive.► see thesaurus at warn2 → forewarned is forearmed —forewarning noun [countable, uncountable]→ See Verb table
Examples from the Corpus
forewarn• The closure order came on a Sunday night, with no forewarning.• There was no-one to explain that leprosy was a disease that gave no forewarning.• She wanted him but couldn't have him and she must deal with that because he had forewarned her.• Barry Hearn forewarned me that the meeting was going to be tough.• Through astrology one could be forewarned of the exact time of his coming.• A police team, forewarned of the raid, had taken up positions inside the bank.• Yet she had timed her appearance so exactly that it seemed as if she had been forewarned of the train's arrival. 