hos·tile / ˈhästl; ˈhäˌstīl/ • adj. unfriendly; antagonistic: a hostile audience he wrote a ferociously hostile attack. ∎ of or belonging to a military enemy: hostile aircraft. ∎ opposed: people are very hostile to the idea. ∎ (of a takeover bid) opposed by the company to be bought.DERIVATIVES: hos·tile·ly adv.