Webster's Revised Unabridged Dictionary -- Volume AB

Besides these, there are other sources from which the prefix a takes its origin.

A 1 (ā wŭn). A registry mark given by underwriters (as at Lloyd's) to ships in first-class condition. Inferior grades are indicated by A 2 and A 3.

A 1 is also applied colloquially to other things to imply superiority; prime; first-class; first-rate.

Aam (ôm or äm), n. [D. aam, fr. LL. ama; cf. L. hama a water bucket, Gr. ?] A Dutch and German measure of liquids, varying in different cities, being at Amsterdam about 41 wine gallons, at Antwerp 36½, at Hamburg 38¼. [Written also Aum and Awm.]

Aard"-vark` (ärd"värk`), n. [D., earth-pig.] (Zoöl.) An edentate mammal, of the genus Orycteropus, somewhat resembling a pig, common in some parts of Southern Africa. It burrows in the ground, and feeds entirely on ants, which it catches with its long, slimy tongue.

Aard"-wolf` (ärd"wlf), n. [D, earth-wolf] (Zoöl.) A carnivorous quadruped (Proteles Lalandii), of South Africa, resembling the fox and hyena. See Proteles.

Aa·ron"ic (·rŏn"ĭk), Aa·ron"ic·al (-ĭ·kal), a. Pertaining to Aaron, the first high priest of the Jews.

Aar"on's rod` (âr"ŭnz rŏd`). [See Exodus vii. 9 and Numbers xvii. 8]

1. (Arch.) A rod with one serpent twined around it, thus differing from the caduceus of Mercury, which has two.

2. (Bot.) A plant with a tall flowering stem; esp. the great mullein, or hag-taper, and the golden-rod.

Ab- (ăb). [Latin prep., etymologically the same as E. of, off. See Of.] A prefix in many words of Latin origin. It signifies from, away , separating, or departure, as in abduct, abstract, abscond. See A-(6).

Ab (ăb), n. [Of Syriac origin.] The fifth month of the Jewish year according to the ecclesiastical reckoning, the eleventh by the civil computation, coinciding nearly with August. W. Smith.

Ab"a·ca (ăb"·k), n. [The native name.] The Manila-hemp plant (Musa textilis); also, its fiber. See Manila hemp under Manila.