Clipping of cathode.
"The technician explained that adding a cath to the circuit would improve electron emission from the vacuum tube."
To catheterize; to fit (someone) with a catheter.
"The nurse asked me to help her cath the patient because he was unable to urinate on his own after the surgery."
A diminutive of the female given name Catherine.
"She introduced her daughter to everyone as Cath, a nickname she had used since kindergarten."