Wiktionary
unsubstantially
adv. In an unsubstantial way.
Usage examples of "unsubstantially".
After the test, you knocked one of the parts haywire so your superior would be blamed for sending people out to risk their lives with apparatus so delicately and unsubstantially built that it won't even last through an ordinary testing.
The lieutenant noted with amazement that a halo flickered unsubstantially around the old man's head.
The rain seemed to roar around me suddenly and the parking lot shifted unsubstantially under my feet.