thievish
/ˈθiːvɪʃ/Definitions
1. adjective
having the characteristics of a thief; given to thieving or stealing
“The thievish behavior of some of the neighborhood kids has been a concern for parents.”
2. adjective (archaic)
given to thieving or stealing; having the nature of a thief
“The thievish tendencies of the young man were evident in his suspicious behavior.”