crux Synonyms

Southern Cross puzzle thrust tickler why bedrock fundamentals puzzler cornerstone alpha and omega tau substance stumper quiddity quintessence rood root roun rubicon soul sphinx crux of the matter jigsaw puzzle nitty-gritty Central Point zero hour papal cross pons asinorum main point Crux Australis heart of the matter decisive point nuts and bolts moment of truth brain-teaser turning point critical point meat and potatoes Gordian knot operoseness leaf node bottom line point of no return key point abstrusity enigma essence essential essentiality focus