Engineering Failure Terminology

adjective Resulting in failure or disaster

• The doctor informed the family that the patient's condition was fatal.
• The car crash was fatal, there were no survivors.
• That disease is no joke, it's fatal if not treated early.
• The fatal mistake in his business plan led to the company's downfall.

adjective describing something that is not firmly fixed or steady; easily changed or disrupted

• The chemical reaction resulted in an unstable compound.
• Her emotions were all over the place, making her feel really unstable.
• I heard that relationship is on the rocks, it's pretty unstable.
• The political situation in the country is becoming increasingly unstable.