The phrase "lock button" refers to a physical or virtual button that you press to make something stay in place and unable to move or change. Full definition
The shifter for the six - speed automatic transmission sits in front of the differential locking button on the console. (cnet.com)
To capture a screenshot on this handset, hold the power / lock button along with the volume down button simultaneously until you feel a vibration or hear a sound. (phoneradar.com)
The roof can be lowered at walking speeds and can also be operated from outside the car, by pressing and holding the door - locking button for three seconds. (newsroom.nissan-europe.com)