居心叵测

harboring unfathomable motives (idiom)

surname Ju

(archaic) sentence-final particle expressing a doubting attitude

to reside / to be (in a certain position) / to store up / to be at a standstill / residence / house / restaurant / classifier for bedrooms

to harbor (evil) intentions / to be bent on / a tranquil heart or mind

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

not / thereupon

unfathomable / unpredictable / treacherous

to survey / to measure / to conjecture