The term SYST. is an abbreviation for the word 'SYSTEM'. It is a set of interacting or interdependent components forming an integrated whole. Systems are used to describe complex structures and processes in many different fields, such as engineering, biology, economics, and computer science. The crossword solution METH. is an abbreviation for the word 'METHOD', which is a systematic procedure, technique, or mode of inquiry used to solve a problem or reach a goal. Methods are often used in combination with systems to achieve desired outcomes.