Answer: permissive

AnswerCrossword Clue
PERMISSIVELenient
PERMISSIVENot doing much disciplining
PERMISSIVELike a teacher who lets you curse
permissiveAllowed but not obligatory; optional
permissivepermitting; granting leave or liberty
permissiveAllowing or characterized by great or excessive freedom of behavior
permissiveAllowing the infection and replication of viruses
permissiveAllowing a biological or biochemical process to occur