noun. A keen groin-juice-detecting device, sold separately from Depends.
Real citation: "As our facility lacks a ballsweatometer, quantitative testing was not possible."
(Keller & O'Brien, ""A Qualitative Examination of the Relationship Between Above-Basal Metabolic Rates and Scrotum Humidity," Feb. 8, 2005, http://icarus.uic.edu/~mobrie3/sack.html)
Made-up citation: "After three straight days in the high nineties, my ballsweatometer officially broke. That's not gonna be good for business. That's not gonna be good for anybody."