F51 most often refers to:
*
North American F-51 Mustang
The North American Aviation P-51 Mustang is an American long-range, single-seat fighter aircraft, fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in April 1940 by a team ...
, an American fighter aircraft
F51 may also refer to:
*
Farman F.51, a French maritime reconnaissance flying boat
* , a Tribal-class destroyer of the Royal Navy
* , a ''Blackwood''-class frigate of the Royal Navy
* , an armed merchant cruiser of the Royal Navy
* , a ''Talwar''-class frigate of the Indian Navy
* Nonorganic
sleep disorder
A sleep disorder, or somnipathy, is a medical disorder of an individual's sleep patterns. Some sleep disorders are severe enough to interfere with normal physical, mental, social and emotional functioning. Polysomnography and actigraphy are tests ...
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