Wiktionary
undangerous
a. Not dangerous.
Usage examples of "undangerous".
He had a hard and not undangerous time of it, for the bulwark of sandbags had been partly swept away, collecting the skat cards that had been scattered all over the room.
When he asked Kubisa about it, she said that Thread was a living organism, not spun and woven as was the undangerous thread that went into clothing.