flunk 
(flŭngk) Informal
(flŭngk) Informal v. flunked, flunk·ing, flunks
v.intr.
To fail, especially in a course or an examination.
v.tr.
1.
a. To fail (an examination or course).
b. To give a failing grade to (a student).
2. To fail (a drug test, as for a performance enhancing substance).
n.
Phrasal Verb: 1. A failure.
2. A failing grade.
flunk out
To expel or be expelled from a school or course because of work that does not meet required standards.
[Origin unknown.]
flunker n.
- Composite order
- composite particle
- composite volcano
- composition
- compositional
- compositionally
- compositionist
- compositive
- compositor
- compositorial
- compos mentis
- compost
- composting toilet
- composure
- compote
- compound
- sweatiness
- sweat lodge
- sweat of brow
- sweat of (one's) brow
- sweat of one's brow
- sweat out
- sweatpants
- sweatshirt
- sweatshop