actinide

Fetched 2026-10-26 (cache).

Synonyms: actiniae, actinic, facticide, actinium, actinism, anticide, actinoid, actinia, antinode, actinian, actinidia

Antonyms: actiniae, actinic, facticide, actinium, actinism, anticide, actinoid, actinia, antinode, actinian, actinidia

Related words from Datamuse; suggestions, not definitions.

Noun

1. Any of the 15 [[radioactive]] [[elements]] of the [[periodic table]] from [[actinium]] to [[lawrencium]] that are [[position]]ed under the [[lanthanide]]s, to which they have similar [[chemistry]].
2. Any of the 14 elements from actinium to [[nobelium]] (lawrencium is excluded by some authors as it is a ''d''-block rather than an ''f''-block element).
3. {{lb|en|dated}} Any of the 14 elements from [[thorium]] to lawrencium (actinium having been mistakenly excluded because it was thought to be a ''d''-block element in the past).

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