Out of touch for decades, say

LONGLOST

Forgotten and missing for an extended period, like a lost treasure.

The clue "Out of touch for decades, say" hints at something missing for a very long time. "Long" suggests an extended period, while "lost" means no longer present or connected. Together, they form "LONGLOST," combining the idea of time ("long") with the state of being missing ("lost"). The phrase "for decades, say" reinforces the length of time implied by "long."