Childless means having no children. A childless couple, remain childless, childless by choice.
The word is neutral in form and not always in effect, which is why childfree has become the preferred term for those who chose it — childless implies a lack, and childfree does not. Involuntarily childless is the careful phrasing where it was not a choice. Note that the compound is Middle English and unchanged, built from child plus -less.
1adjectivechildlessHaving no children.
“The childless couple left their house to their nephew in their will.”
childless is a state of having no children.
Middle English childles is child plus -less. Child itself is Old English cild, with no clear relatives outside Germanic.
Middle English
childles
English, today
childless
From Middle English childles; equivalent to child + -less.
Etymology from Wiktionary, CC BY-SA