ar

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Variant of are².
2. n. The letter r.

Century Dictionary and Cyclopedia

1. n. The name of the letter R. Also formerly spelled arre.
2. n. See arr.
3. n. Obsolete forms of are, ere, or, ore, etc.
4. n. The assimilated form, in Latin, etc., of ad-before r; in older English words a restored form of Middle English and Old French a-, the regular reduced form of Latin ar-, as in array, arrange, etc.
5. n. A suffix of nouns denoting an agent; a variant of -er, as in beggar, liar, formerly and properly begger, etc.
6. n. A suffix of Latin origin, occurring in some nouns, as in bursar, medlar, mortar, vicar, etc.
7. n. A suffix, of Latin origin, of adjectives (and of nouns thence derived), being equivalent to -al, for which it is used when l precedes, as in alar, polar, regular, singular, etc. (see -al, and compare -ar); of nouns, as in altar, collar, pillar, scholar, etc. In these nouns and other old words -ar is an alteration (to suit the Latin) of the Middle English -er, from Old French, or (as in scholar) from Anglo-Saxon.
8. n. In heraldry, a common abbreviation of argent.
9. A simplified spelling of are.
10. etc. Points of flexure in the curves of cooling of iron and steel.

Wiktionary

1. n. The name of the Latin script letter R/r.

GNU Webster's 1913

1. conj. obsolete Ere; before.

WordNet 3.0

1. n. a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
2. n. a unit of surface area equal to 100 square meters
3. n. a state in south central United States; one of the Confederate states during the American Civil War