nu·tri·tion 
(n
-tr
ĭsh
ən, ny
-)
n.1. The process of nourishing or being nourished, especially the process by which a living organism assimilates food and uses it for growth and for replacement of tissues.
2. The science or study that deals with food and nourishment, especially in humans.
3. A source of nourishment; food.
[Middle English nutricion, from Old French nutrition, from Late Latin nūtrītiō, nūtrītiōn-, from Latin nūtrītus, past participle of nūtrīre, to suckle; see (s)nāu- in the Appendix of Indo-European roots.]
nu·trition·al adj.
nu·trition·al·ly adv.