the GNU version of the Collaborative International Dictionary of English
adj. That may be impeached; liable to impeachment; chargeable with a crime.
The Century Dictionary and Cyclopedia
Liable or making liable to be impeached; chargeable with wrong-doing; censurable; liable to be called in question.
Word Usage
"D of Pennsylvania said earlier this year that the White House had offered him a job to get him not to run for the Senate, Issa suggested that was an "impeachable" offense."