o·rex·in 
(ô-rĕksĭn)
(ô-rĕksĭn)n.
Either of two neuropeptide hormones synthesized in the hypothalamus that regulate sleep and wakefulness and whose dysfunction causes narcolepsy. Also called hypocretin.
[Greek orexis, appetite (from the view that orexin stimulates appetite; see ANOREXIA) + -IN.]
- semipolitical
- semiporcelain
- semiprecious stone
- semiprivate
- semipro
- semiprofessional
- semiprofessionally
- semipublic
- semipublicly
- semiquaver
- semiretired
- semiretirement
- semirigid
- semiround
- semirural
- semiskilled
- semisoft
- semisolid
- semispherical
- semisub
- semisubmersible
- semisweet
- semisynthetic
- Semite
- semiterrestrial