Wiktionary
lightened up
vb. (en-past of: lighten up)
Usage examples of "lightened up".
The first one was rather grim, but they've gradually lightened up.
As she still listened to the Goth, as she felt the birth of new feelings within her while he spoke, her cheeks glowed, her features lightened up, her very form seemed to freshen and expand.
Rodek, Toq noticed, had lightened up considerably these past few months.
Then she, too, lightened up, the tension draining out of her body.
The rain had finally lightened up, and I was lying in front of one of the open French windows on the carpeted floor, letting the cool air that the storm had brought into the city play over my face and lull me into the first really decent rest I’.
Her voice had lightened up just a bit, but now it was low and suspicious again.