Historically known as "the vagina of the mouth," this area has gained recent popularity among "headventurers" for remaining constantly wet and sensitive.
Headventurer:"Sheila, lets try something new"

Sheila: "oh ya, put it in my undertongue"
by Gorilla Adam December 6, 2009
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1. (n): Area on the bottom of the tongue where the tongue attaches to the rest of the mouth. (You know what i'm talking about- it's all veiny and full of saliva)
Girl: "I was picking my teeth with a toothpick and I slipped and stabbed my undertongue today!"

Guy: "Wow. You impaled your undertongue? Gross."
by K Floss December 6, 2009
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The title given to a person with a severe lack of tongue action during kissing . We’re talking less than sub 20% tongue to kiss ratio. Refer to overtonguer.
She’s a total undertonguer ... she needs to get more movement happening, it’s like kissing a mannequin
by Chippawood April 14, 2019
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