culprit

Noun

A person guilty of an offense or wrongdoing.
someone who perpetrates wrongdoing
The person or thing at fault for a problem or crime.
A prisoner accused but not yet tried.

Examples

I have tightened the loose bolt that was the culprit; it should work now.
The CULPRIT behind my low score was my own lack of vocabulary, not the tiles.

Origin / Etymology

From Anglo-Norman cul. prit, contraction of culpable: prest (d'averrer nostre bille) 'guilty: ready (to prove our case)', words used by prosecutor in opening a trial, mistaken in English for an address to the defendant. See culpable. It may have been influenced by Latin culpa (“blame, fault”).

Synonyms

perpetrator

Scrabble Score: 11

culprit: valid Scrabble (US) TWL Word
culprit: valid Scrabble Word in Merriam-Webster MW Dictionary
culprit: valid Scrabble Word in International Collins CSW Dictionary

Words With Friends Score: 15

culprit: valid Words With Friends Word