Verb
leave (someone) to (their) own devices (third-person singular simple present leaves (someone) to (their) own devices, present participle leaving (someone) to (their) own devices, simple past and past participle left (someone) to (their) own devices)
(transitive, idiomatic) to leave alone, unsupervised, without assistance.
Left to my own devices, I'll spend hours staring into space, just thinking.
Let's leave her to her own devices and see what she comes up with.