Excitement caused by the short stream (6)
I believe the answer is:
thrill
'excitement' is the definition.
(I know that thrill is a type of excitement)
'the short stream' is the wordplay.
'short' means to remove the last letter.
'stream' becomes 'rill' (rill is a kind of stream).
'the' with its final letter taken away is 'th'.
'th'+'rill'='THRILL'
'caused by' is the link.
(Other definitions for thrill that I've seen before include "Almost pleasant sensation of fright" , "Buzz" , "A wave of feeling or excitement" , "Excited sensation" , "Exciting sensation, wave of feeling" .)