WordNet sense 1 (agitation resulting from active worry):

fret, lather, stew, swither, lather

WordNet sense 2 (salty fluid secreted by sweat glands):

perspiration, sudor

WordNet sense 3 (use of physical or mental energy; hard work):

effort, exertion, travail, elbow grease

WordNet sense 4 (excrete perspiration through the pores in the skin):

perspire, sudate