fatigue:great tiredness, usu resulting from hard work or exercise 疲乏; 疲劳; 疲倦: We were all suffering from fatigue at the end of our journey. 我们到旅程终点时全都累垮了.
tire:(cause a person or an animal to) become weary or in need of rest (使人或动物)疲劳, 疲倦: She's got so much energy she never seems to tire. 她精力充沛--似乎从不感到疲倦. * Old people tire easily. 老年人容易疲倦. * The long walk tired me (out). 我长途步行之后很累.
fatigue 是名词
tired 是形容词