One who abets; an instigator of an offense or an offender.(noun)
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "abetter" in a sentence
"DiNapoli was abetter choice than Spitzer's candidate, who was subsequently compelled to resign as City Finance Commissioner because of sundry irregularities whose details you can find with the aid of Google."
"Judge Maas noted Mr. Elie faces the charges as either a principal or an aider and abetter with the others in the alleged scheme."
"Look at the tracks, take a picture and post them, gives you abetter idea of what type of animal it was."