The term 'Sibilant Talk' can be described as a type of speech characterized by the use of sibilants, which are consonants that produce a hissing sound. The crossword solution for this term is 'Lisp, ' which is a programming language developed in 1958 by John McCarthy. Lisp is a high-level language that is used for artificial intelligence and symbolic computation. It is known for its ability to process symbolic information efficiently and for its use of parentheses to denote code blocks.