What is the meaning of Sappy?

Excessively sweet, emotional, nostalgic; cheesy; mushy. (British equivalent: soppy)

Having (a particularly large amount of) sap.

Juicy.

Spongy; Having spaces in which large quantities of sap can flow.

Musty; tainted; rancid.

sappy (having lots of sap or sapwood)

Source: wiktionary.org