E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Probably a corruption of Abron, meaning auburn. Halliwell quotes the following from Coriolanus, ii. 3: Our heads are some brown, some black, some Abram, some bald. And again, Where is the eldest son of Priam, the Abram-coloured Trojan? A goodly, long, thick Abram-coloured beard.Blurt, Master Constable.
Hall, in his Satires, iii. 5, uses abron for auburn. A lusty courtier with abron locks was fairly furnishëd.