Spit that’s found in one’s mouth (6)
I believe the answer is:
tongue
This could be a double definition.
'spit' is the first definition.
(I know that spit can be written as tongue)
'found in one's mouth' is the second definition.
'tongue' can be an answer for 'mouth' (thesaurus). I'm unsure of the 'found in one's' bit.
'that's' is the link.
Can you help me to learn more?
(Other definitions for tongue that I've seen before include "manner of speaking" , "Ability to speak - a language" , "dialect" , "Style of speaking; lick" , "Projecting strip" .)