first oxidation product of alcohol, 1833, discovered in 1774 by German-born Swedish chemist Carl Wilhelm Scheele, the name said to have been coined by German chemist Justus von Liebig from abbreviation of Modern Latin alcohol dehydrogenatum "dehydrogenated alcohol." Related: Aldehydic.

"a conferring, act of giving gratuitously," 1773, from bestow + -al (2). Alternative bestowment is from 1730.

"act of betrothing," 1825, from betroth + -al (2). Earlier in same sense were betrothment (1580s), betrothing (14c.).

"colorless liquid formed by the action of chlorine on alcohol," apparently coined by German chemist Justus von Liebig in 1833 from elements from chlorine + alcohol. Later chiefly in chloral hydrate (1874).

1660s, "first, earliest, existing from the beginning," especially in reference to inhabitants of lands colonized by Europeans, from aborigines (see aborigine) + -al (1). The specific Australian sense is attested from 1820, with capital A-. The noun meaning "an original inhabitant, an autochthon" is attested from 1760. Related: Aboriginally; aboriginality (1848); aboriginalism (1859).

1650s, "pertaining to an abyss," formed in English from abysm + -al (1). Perhaps only a dictionary word before 19c. The weakened sense of "extremely bad" is attested by 1904, perhaps from abysmal ignorance (suggestive of its "depth"), an expression attested from 1847. Related: Abysmally.

1690s, "unfathomable, unsearchably deep, like an abyss," from abyss + -al (1). Since 19c. mainly "inhabiting or belonging to the depths of the ocean" (used especially of the zone of ocean water below 300 fathoms), though in 19c. abysmal was more common in oceanography.

"pertaining to accent," c. 1600, from Latin accentus (see accent (n.)) + -al (1). Related: Accentually; accentuality.

"act or process of accruing," 1782, from accrue + -al (2). Compare accretion. Another older noun was accruement (c. 1600).

early 15c., aquitaille, "payment of debt or retribution;" see acquit + -al (2). Sense of "a release from debt or obligation" is from mid-15c.; that of "freeing from charge or offense" (by legal process) is from 1530s.