Webster's Revised Unabridged Dictionary · 1913

Sappy

Sappy , adjective

[From 1st Sap.]

1.
Abounding with sap; full of sap; juicy; succulent.
2.
Hence, young, not firm; weak, feeble.
When he had passed this weak and sappy age. — Hayward
3.
Weak in intellect. [Low]
4.
(Botany) Abounding in sap; resembling, or consisting largely of, sapwood.

Sappy , adjective

[Compare Latin sapere to taste.]

Musty; tainted. [Obsolete]