abysm (n.) Look up abysm at Dictionary.com
"bottomless gulf, greatest depths," now chiefly poetic, c.1300, from Old French abisme (Modern French abîme), from Vulgar Latin *abyssimus (source of Spanish and Portuguese abismo), which represents either a superlative of Latin abyssus or a formation on analogy of Greek-derived words in -ismus; see abyss.