Cadr

//ˈkɑːdə// noun

noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    Car of the cdr in Lisp. The second element in a list.

    "If we let x denote the tree (1 2 3), then the car of x is 1, the cdr of x is (2 3), the cadr of x is 2, the caddr of x is 3, and the cdddr of x is nil."

  2. 2
    Initialism of Clean air delivery rate, a measure of cleaned air from air purifiers. US, abbreviation, alt-of, initialism, uncountable

Example

More examples

"If we let x denote the tree (1 2 3), then the car of x is 1, the cdr of x is (2 3), the cadr of x is 2, the caddr of x is 3, and the cdddr of x is nil."

Etymology

Contraction of car of the cdr.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.