at fault

fault  (fôlt) n. 1. a. A character weakness, especially a minor one. b. Something that impairs or detracts from physical perfection; a defect. See Synonyms at blemish. c. A mistake; an error. d. A minor offense or misdeed. 2. Responsibility for a mistake or an offense; culpability. See Synonyms at blame. 3. Geology A fracture in the continuity of a rock formation caused by a shifting or dislodging of the earth's crust, in which adjacent surfaces are displaced relative to one another and parallel to the plane of fracture. Also called shift. 4. Electronics A defect in a circuit or wiring caused by imperfect connections, poor insulation, grounding, or shorting. 5. Sports A bad service, as in tennis. 6. Obsolete A lack or deficiency. v. fault·ed, fault·ing, faults v.tr. 1. To find error or defect in; criticize or blame. 2. Geology To produce a fault in; fracture. v.intr. 1. To commit a mistake or an error. 2. Geology To shift so as to produce a fault. Idioms: at fault 1. Deserving of blame; guilty: admitted to being at fault. 2. Confused and puzzled. find fault To seek, find, and complain about faults; criticize: found fault with his speech. to a fault To an excessive degree: generous to a fault. [Middle English faulte, from Old French, from Vulgar Latin *fallita, from variant of Latin falsa, feminine past participle of fallere, to deceive, fail.]

fault top: normal fault center: reverse fault bottom: strike-slip fault

Thesaurus

Adj.

1.

at fault - deserving blame; "admitted to being at fault" guilty - responsible for or chargeable with a reprehensible act; "guilty of murder"; "the guilty person"; "secret guilty deeds"