Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
inedible, poisonous, uneatable, unedible (adjs.)
Something inedible is “unfit to be eaten,” and so are things unedible and uneatable: The bread was so maggotty as to be inedible [unedible, uneatable]. (Inedible seems to be the term of choice.) Something poisonous, however, would be capable of injuring or killing. Poisonous is also used hyperbolically of food, simply to mean that it tastes awful, “as though it were poisoned,” and it has a transferred sense used of people’s behavior: He has a poisonous disposition.
