unscrupulous (adj.)
- artful
- conscienceless
- corrupt
- corrupted
- crafty
- criminal
- crooked
- cunning
- dark
- deceitful
- devious
- dishonest
- dishonorable
- disingenuous
- doubtful
- dubious
- evasive
- evil
- faithless
- false
- felonious
- fishy
- fraudulent
- ill-gotten
- immoral
- improper
- inaccurate
- indirect
- inexact
- insidious
- knavish
- mercenary
- perfidious
- questionable
- roguish
- rotten
- scheming
- shady
- shameless
- shifty
- sinister
- slippery
- sly
- sneaky
- suspicious
- treacherous
- tricky
- unconscientious
- unconscionable
- uncritical
- underhand
- underhanded
- unethical
- unexacting
- unprincipled
- unpunctual
- unsavory
- unseemly
- untrustworthy
- venal
- wicked
- wrongful
