Define frustration: the act of frustrating; the state or an instance of being frustrated â frustration in a sentence the act of frustrating; the state or an instance of being frustratedâ¦ See the full definition
The definition of a blot is a spot or stain, whether physical or on a person's character. An example of a blot is an ink stain on a shirt. Blot means to dry, soak up or remove. An example of to blot is to wipe up tipped over milk with a paper towel.
This idiom, first recorded in 1516, uses the verb to blot in the sense of making something illegible by spotting or staining it with ink. The New Testament has it (Acts 3:19): Repent ye ... that your sins may be blotted out.