https://www.cs.drexel.edu/~jpopyack/Courses/AI/Sp20/extras/LISP/CADDDR.html

where "cou" is as in the word "could".

Any pronunciation you like is fine, but it
really should differentiate things like
cddr and caddr and cadar.  IOW, in particular
it needs to distinguish things like cdr and
cdar.