In the defense of motor discussions the US standard for name plates for single phase motors is 115 (or 230) volts. I checked several in my shop and they were compliant.
Although the target current supply voltage standard is 120/240 nominal, the allowable supply voltage is 114 to 126 (plus or minus 5%). That, BTW, is the Range A described in ANSI-C84.1-2011. Range B values are 110 to 127 volts.
Historically, supply voltage has been 110, 115, and even 117 volts in different places.
When someone discusses AC power I personally read 110, 115, and 120 as identical in my head. What's a few volts among physical and forum friends. When someone says 110v I know what they mean. They say 120v I know what they mean. I look at it this way - in the home and shop we are using "110v" not as a value but as a name (label) to describe a thing to another person - the thing is the power we get from a typical receptacle anywhere. We seldom measure it with a meter and use it as an actual value - we don't care if it is really 110v or 118v or 122v.
BTW, if Edison had had his way, the electrical power grid would be DC instead of AC. The War of Currents between Edison and Tesla (and later, Westinghouse) was eventually resolved when it was demonstrated that high voltage AC was far more efficient to send over long distances. And AC is far easier to convert to any other voltage (simple transformer) AND cheap/easy to convert to DC where needed (simple rectifier and capacitor).
Some references:
American National Standard for Electric Power Systems and Equipment – Voltage Ratings (60 Hertz)
ANSI C84.1 – 2011
published by National Electrical Manufacturers Association (NEMA).
Pacific Gas and Electric
Voltage Tolerance Boundary
UNITED STATES DEPARTMENT OF AGRICULTURE
Rural Utilities Service
BULLETIN 1724D-113
SUBJECT: Voltage Levels on Rural Electric Distribution Systems
JKJ