Synonyms for Out Of Sight (same or very similar meaning)
WordNet sense 1 (not accessible to view):
hidden, concealedWordNet sense 2 (impossible or nearly impossible to see; imperceptible by the eye):
invisible, unseeableWordNet sense 3 (no longer visible):
out of viewWordNet sense 4 (quietly in concealment):
doggo, in hidingFrom the ODE community, based on WordNetadd/edit