A lot vs. Alot: 9 Grammatical Pitfalls
1816, American English dialectal contraction of ordinary (adj.). "Commonplace," hence "of poor quality, coarse, ugly." By c.1860 the sense had evolved to "mean, cantankerous." Related: Orneriness.
Mean and irascible; ill-tempered: He wasconfident and ornery on the mound
[1816+; fr a dialect pronunciation of ordinary]