IPA: /ˈʃɪf.tɪ.li/
KK: /ˈʃɪf.tɪ.li/
In a way that suggests someone is being deceitful or not trustworthy.
He looked at me shiftily, as if he was hiding something.
Shiftily is formed from "shift" (from Old English "sciftan", meaning to change or move) and "-ly" (meaning in a manner of). The word describes doing something in a manner that involves change or movement, often with a sense of slyness or deceit.
Think of 'shifting' as changing or moving something, and the '-ly' means in that manner. So, shiftily means doing something in a sly or deceitful way.