CADR is an AGC assembly directive defining a "complete address" including a memory bank, in this case a subroutine to be called by the preceding BANKCALL (TC = transfer control, i.e., store return address and jump to subroutine), which switches to the memory bank specified in the CADR before jumping to the address specified in the CADR.
For a brief explanation of AGC subroutine calls, see [1].
CAR and CDR in Lisp come from the original implementation on the IBM 704, where pointers to the two components of a cons cell were stored as the (C)ontents of the (A)ddress and (D)ecrement fields of a (R)egister (memory word).
(CADR x) is just shorthand for (CAR (CDR x)), i.e., a function that returns the second element of a list (assuming x is a well-formed list).
[1] https://epizodsspace.airbase.ru/bibl/inostr-yazyki/American_...
“I tried to keep to Shelley’s unusual (and non-standard) rhyme scheme for the sonnet, but I departed from it in the second-to-last line for poetic reasons. For a language which excels in stealing words from other cultures, English has an appalling lack of rhymes.”
Perhaps with deeper analysis, and a few choice new words this issue could be remedied.
Although that’s a paradoxically tedious engineering solution to improve a languages beauty.
From another angle how comes other languages are more poetic, are they older and have had more time to evolve to be more poetic? Or were the speakers who wrought the language just more poetic.