fault
UK[fɔːlt]US[fɔːlt]
n
Responsibility for a mistake or for something bad that has happened.
n
A weakness or bad aspect of someone's character.
n
A mistake or problem in something that makes it less effective or correct.
n
(Geology) A large crack in the rocks that form the Earth's crust, where the rocks have moved against each other.
v
To find a mistake or weakness in someone or something; to blame or criticize.
Etymology
The word 'fault' entered Middle English from the Old French 'faute', which itself derived from the Vulgar Latin 'fallita', a noun form related to the feminine past participle of the Latin verb 'fallere', meaning 'to deceive, trip, cause to fall, or be lacking'. The core semantic thread from Latin to modern English is one of 'failing' or 'falling short'. This evolved from the literal sense of stumbling or deceiving to the abstract notions of imperfection, blameworthiness, and, in geology, a fracture where the earth's crust has 'slipped' or 'failed' to remain continuous. The journey from a verb of action ('to trip up') to a noun denoting the resulting state of error or defect illustrates a classic path of semantic evolution.
Analysis
The word 'fault' is a simplex word borrowed into English as a whole unit from Old French. Its ultimate Latin root is 'fallere' (to deceive, disappoint, escape notice of). In English, it functions as a complete lexical root.
Examples
The mechanic found a major fault in the engine's wiring.
It's my fault that we missed the train; I misread the schedule.
The San Andreas Fault is a well-known geological feature in California.