Wiktionary
untell
vb. (context transitive English) To withdraw or retract (something tell); never to have told.
Usage examples of "untell".
When she arrived, robed in purple, comely beyond his belief, accompanied by the alien, Rei, he nodded to Untell, awake, tense, seated at the main console.
Somewhere behind his untelling features lay the answers— answers to everything.
His gaze was deep, his round eyes untelling, and George became suddenly unsure of the spontaneous decision he’d made back on the planetoid, the one that prevented t’Cael the destiny of his choice—death—as opposed to the obscure future he now faced.
He was staring down at her now, his expression as untelling as ever, but she distinctly sensed he might be waiting for his kiss.