The crossword solution for the term 'Why and Wherefore' is 'RATIONALE'. The term 'Why and Wherefore' is an old English phrase that means 'the reasons behind something'. It is often used to refer to the underlying reasons or motivations for a particular action or decision. RATIONALE is derived from the Latin word 'RATIO', which means 'REASON'. Therefore, the crossword solution of 'RATIONALE' for the term 'Why and Wherefore' is an appropriate choice as it accurately reflects the meaning of the phrase.