perspiration (n.)
1610s, from French perspiration (1560s), noun of action from perspirer "perspire," from Latin perspirare "blow or breathe constantly," from per- "through" (see per) + spirare "to breathe, blow" (see spirit (n.)). Applied to excretion of invisible moistures through the skin (1620s), hence used as a euphemism for "sweat" from 1725.