The Collaborative International Dictionary of English v.0.48:
Perspire \Per*spire"\, v. i. [imp. & p. p. Perspired; p. pr. & vb. n. Perspiring.] [L. perspirare to breathe through; per + spirare. See Per-, and Spirit.] 1. (Physiol.) To excrete matter through the skin; esp., to excrete fluids through the pores of the skin; to sweat. [1913 Webster] 2. To be evacuated or excreted, or to exude, through the pores of the skin; as, a fluid perspires. [1913 Webster]