1.nounA stick or rod used to measure the depth of a liquid. Often used to check the level at which a liquid in an opaque or inaccessible tank or reservoir stands; gauge.
"I haven't checked the oil level of my car's motor since I lost the dipstick three months ago."
2.nounA penis.
3.nounA useless person of inferior intellect; a dipshit.
"That referee is a right dipstick."
4.verbTo check (a person) for their understanding of something, as of a lesson, or attitude toward something.