adj contaminating with illegality; exposing to seizure and forfeiture.
2. infectious ·adj corrupting, or tending to corrupt or contaminate; vitiating; demoralizing.
3. infectious ·adj capable of being easily diffused or spread; sympathetic; readily communicated; as, infectious mirth.
4. infectious ·adj having qualities that may infect; communicable or caused by infection; pestilential; epidemic; as, an infectious fever; infectious clothing; infectious air; infectious vices.