A sheep in its second year, between weaning and shearing. So now nobody can look down their aristocratic nose at you for not knowing a teg from a ewe.
And while on the sheep theme, see also: ‘hefted’, ‘shearling’ and above all my resplendent review of James Rebanks’ The Shepherd’s Life.
‘That he did not know a geranium from a carnation, an oak from a birch tree, a mastiff from a greyhound, a teg from a ewe … all this and much more amazed Orlando.’
Source: Virginia Woolf, Orlando, ed. Rachel Bowlby, Oxford: World’s Classics, 1992, p. 88-89 and 324