unrestrictive
broad-minded
culpably negligent
derelict
freethinking
inadvertent
inattentive
laissez-faire
latitudinarian
lax
liberal
libertarian
libertine
loose
neglectful
neglecting
negligent
noninterfering
off-guard
open-minded
overly permissive
permissive
procrastinating
relaxed
remiss
scamping
skimping
slack
slighting
slurring
tolerant
unbigoted
uncircumspect
unguarded
unrigorous
unwary
unwatchful