Other forms: foundations
The foundation of a building is the solid base below ground that everything above rests on. Lay the foundations, the foundations are cracked, dig the foundations.
It is usually plural in that sense and singular in every other. A foundation is also an organisation set up to fund something — a charitable foundation — and the basis of an argument or a belief: the foundation of the whole case. In cosmetics, foundation is the base layer of make-up, named for the same reason. Note foundation course, which in British education is a preparatory year, and the fixed phrase without foundation, meaning an accusation with no evidence behind it.
1nounfoundationThe solid base a building stands on.
“The foundations were dug in October.”
2nounideaThe idea or fact something rests on.
“The whole theory has no foundation in evidence.”
3nounorganisationAn organisation set up to provide money for a purpose.
“The foundation gives money to young artists every year.”
4nounlayerA base layer of make-up.
“She wears very little foundation.”
Too few real examples of this word to estimate which sense is commonest.
Latin fundatio comes from fundus, the bottom — the same word behind fund, fundamental and profound. A foundation is the bottom of something, and every figurative use is that picture applied upwards.
Proto-Indo-European
*ǵʰewd-
Latin
fundātiō
Old French
fondacion
Middle English
foundacioun
English, today
foundation
From Middle English foundacioun, from Old French fondacion, from Latin fundātiō. From Middle English foundacioun, fundacioun, from Old French fondacion, from Latin fundātiō (“founding, foundation”).
Etymology from Wiktionary, CC BY-SA