To impute means “to attribute or ascribe”. Unlike a lot of my previous words, this one isn’t unusual or obscure in any way. It comes from Latin imputare, a combination of in-, meaning “upon”, and putare, meaning “reckon, clear up, trim, prune, settle” (OED). Related words include dispute, compute, and even amputate.
As explained by Dictionary.com, the word impute can be used to ascribe a characteristic to something: for example, “the gracefulness so often imputed to cats”. It can also be used to identify the cause of something, or to place blame: he “imputed the rocket failure to a faulty gasket”, for example.
The word also has a more specific meaning in a legal sense: “to ascribe to or charge (a person) with an act or quality because of the conduct of another over whom one has control or for whose acts or conduct one is responsible”. The noun form imputation has specific meanings in economics, religion, and more; see its entry on Wikipedia if you’re curious.