not tractable; difficult to manage or mold; "an intractable disposition"; "intractable pain"; "the most intractable issue of our era"; "intractable metal"
a methodical examination or review of a condition or situation; "he made an audit of all the plants on his property"; "an energy efficiency audit"; "an email log audit"
attend academic courses without getting credit
examine carefully for accuracy with the intent of verification; "audit accounts and tax returns"