Session (7)
![Ross](/clue/static/ross-mug.min.png)
'session' is the definition.
(I know that session can be written as sitting)
This is the entire clue.
(Other definitions for sitting that I've seen before include "Session of spiritualists or court" , "such an easy target" , "Well placed" , "Being portrayed" , "On a seat" .)
(Other definitions for jam that I've seen before include "Preserve - predicament" , "Spread; improvise (jazz)" , "Preserve; pack tightly" , "Fruit preserve" , "Block signals" .)