dipstick
/ˈdɪpˌstɪk/Definitions
1. noun
A rod or stick with a hole at one end, used for measuring the level of a liquid, especially engine oil, in a vehicle.
“You need to check the oil level with the dipstick.”
2. verb
To measure the level of a liquid using a dipstick.
“Dipstick the oil to see if it’s low.”