The Collaborative International Dictionary of English v.0.48:
Antisyphilitic \An`ti*syph`i*lit"ic\, a. (Med.) Efficacious against syphilis. -- n. A medicine for syphilis. [1913 Webster]WordNet (r) 3.0 (2006):
antisyphilitic n 1: a drug (or other chemical agent) that is effective against syphilis