From the Ecloque Wordsmith cited what does "yeaned" mean?
"She dropped her new-yeaned twins on the bare flint, "

Joke on me.I thought it was a typo, but:
Webster's 1913 Dictionary

Definition: \Yean\, v. t. & i. [imp. & p. p. {Yeaned}; p. pr. & vb. n.
{Yeaning}.] [AS. e['a]nian, or gee['a]nian; perhaps akin to
E. ewe, or perhaps to L. agnus, Gr. ?. Cf. {Ean}.]
To bring forth young, as a goat or a sheep; to ean. --Shak.

But I wonder how Tityrus can be comfortable resting on
a "slender oat".

Thanks for the def., Dr. Bill--I thought your sentence was a typo, too. Don't think I'll go look at the eclogue, though--that one line is depressingly ominous.

resting on a "slender oat".

must be a super model