What does "strenuous" mean?

Strenuous: Eagerly pressing or urgent; zealous; ardent; earnest; bold; valiant; intrepid; as, a strenuous advocate for national rights; a strenuous reformer; a strenuous defender of his country. And spirit-stirring wine, that strenuous makes. Chapman. Strenuous, continuous labor is pain. I. Taylor. -- Stren"u*ous*ly, adv. -- Stren"u*ous*ness, n.