Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
abysmal, abyssal (adjs.)
Abysmal means “very deep,” but mostly in figurative senses: Consider the cliché abysmal ignorance, or Her concentration was abysmal. It means “deeply awful,” “incredibly bad,” and is pejorative in all senses, as is the much-used intensifying adverb, abysmally (She was abysmally gloomy). Abyssal is a technical term in oceanography, referring to the greatest depths (the abyssal zone).
