Webster's New World Medical Dictionary

drain 1
A device for removing fluid from a cavity
or wound, typically a tube or wick. 
2
As a verb, to
allow fluid to be released from a confined area.
DRD
See 
dopa-responsive dystonia.
dream
A series of thoughts, visions, and other
sensations that occupy the mind during sleep.
Dreams occur during that part of sleep when there
are rapid eye movements (REM sleep). People have
three to five periods of REM sleep per night, which
usually come at intervals of 1 to 2 hours and are
quite variable in length. An episode of REM sleep
might be brief and last just 5 minutes, or it might be
much longer. Experiments have shown that a person
can communicate with a person who is dreaming.
Dreaming is not uniquely human; cats and dogs
dream, judging from the physiologic features, and
so, apparently, do many other animals. The content
of dreams is sometimes the topic of psychoanalysis.
Although this method of therapy is less common
today than it once was, some physicians still look at
dreams as a diagnostic clue to medical disorders.
For example, children with bipolar disorder have
been found to frequently have a particular type of
nightmare, and especially lucid dreams are a side
effect of certain medications. These clues indicate
that chemicals in the brain, as well as life events and
individuals’ preoccupations, influence dreams. See
also 
REM sleep.
drip
Short for intravenous drip, a device for
administering a fluid drop-by-drop into a vein via an
intravenous (IV) route.
drug, ACE-inhibitor
See 
ACE inhibitor.
drug, anti-angiogenesis
See 
anti-angiogene-
sis drug.
drug, antihypertensive
See 
antihypertensive.