Or from Latin baculum a stick, because the squire would practice with a staff, not a sword. Meaning evolved from knight in training to young unmarried man (early 14c.). Bachelor party as a pre-wedding ritual is from 1882.
A transcutaneous electrical nerve stimulation (TENS) unit is a device that sends small electrical currents to targeted body parts. These currents are used to relieve pain. Some TENS units are designed for use in a hospital or healthcare facility.
1 Do not place electrodes on broken or irritated skin. 2  Do not drive while using a TENS unit. 3  Do not use the device in the shower or bathtub. 4  Do not use a TENS unit with heating pads or cold packs. 5  Do not use TENS while sleeping. Do not place electrodes on broken or irritated skin. 2  Do not drive while using a TENS unit. 3  Do not use the device in the shower or bathtub. 4  Do not use a TENS unit with heating pads or cold packs. 5  Do not use TENS while sleeping.