observationally stable

Fetched 2026-10-26 (cache).

Datamuse reports no synonyms or antonyms for this word.

Adjective

1. Of a [[nuclide]] ([[isotope]]): theoretically capable of [[radioactive decay]] (on the grounds that it would be [[energy]]-profitable), but not having been observed to do so.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.