Definition of piths:
(n) :
(figurative) The central or innermost part of something; the core, the heart.
(n) :
(figurative) The essential or vital part of something; the essence.
(n) :
(figurative) Chiefly in of (great) pith and moment: gravity, importance, substance, weight.
(n) :
(figurative) Physical power or strength; force, might.
(n) :
(figurative) A quality of courage and endurance; backbone, mettle, spine.
(n) :
(figurative) The energy, force, or power of speech or writing; specifically, such force or power due to conciseness; punch, punchiness.