A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

send someone down • send someone up
send someone down —(coll.) 
1
. dismiss a student from a uni-
versity: He escaped prosecution because of his family back-
ground but he was sent down from the University. 2. (also:
send someone down the river) send a person to prison: The last
case was about a plumber who charged a pensioner £2,000 to
do a job that other plumbers said was worth £50. They sent
him down for two years.
send someone up —
1
. (UK coll.) make fun of a person: Much
British humor consists in sending up the customs and leading
figures of the country. 2. (also: send someone up the river) =
send someone down 2: He did a lot of breaking and entering
before the judge sent him up about fifteen years ago.
Note: 
The expression is not related in meaning to the phrase
send someone flying
— trip or hit a person causing him to fall:
I gave him a great, big shove that sent him flying into the pile
of wood at the back of the garage.
send someone out to grass • send someone to grass
send someone out to grass —(coll., also: put someone out to
grass) 
1
. send smb. on a holiday: There were a few strange
faces: three or four wives with children sent out to grass from
Athens. 2. send a person into retirement: The consultant-in-
charge of our clinic has accepted retirement. At three score
and ten it is time he was sent out to grass.
send someone to grass —(coll.) knock a person down: In the
fifth round Billy caught Harry with a solid right and sent him
to “grass” not to rise again.
send something by return • send something in
 return
send something by return —send smth. in the next post: You
can request your free copy of our catalogue by filling in our
request form and we’ll send it by return.
send something in return —send smth. in exchange for smth.
else: The bills they send out, and the checks customers send
in return, account for about 25 percent of the mail stream.