cowardly
disloyal
fearful
Sabbath-breaker
apostate
arrant coward
atheist
atheistic
backslider
backsliding
bad egg
bad lot
base
black sheep
blackguardly
blasphemer
blasphemous
bolter
caitiff
collaborationist
collaborative
collaborator
convert
coward
craven
dastard
dastardly
defector
degenerate
degraded
derelict
deserter
disaffected
dunghill
dunghilly
faithless
fallen
fallen angel
fallen from grace
false
fickle
fifth columnist
impious
inconstant
infamous
irreligious
irreverent
quitter
doughty
duplicitous
faint-hearted
false-hearted
heav'nly
highly-seasoned
honorless
meanspirited
neighbouring
new-made
perfidious
retrogressive
self-deceived
slothful
sycophantic
truant
unbelieving
unfaithful
untrustworthy
unwarlike
white-livered