pre·con·di·tion 
(prē′kən-dĭshən)
(prē′kən-dĭshən)n.
A condition that must exist or be established before something can occur or be considered; a prerequisite.
tr.v. pre·con·di·tioned, pre·con·di·tion·ing, pre·con·di·tions
To condition, train, or accustom in advance.
- undershot
- undershrub
- underside
- undersign
- undersigned
- undersize
- undersized
- underskirt
- undersleeve
- underslung
- undersoil
- undersold
- under (someone's) nose
- under someone's nose
- under (someone's) thumb
- under someone's thumb
- underspin
- understaff
- understand
- understandability
- understandable
- understandably
- understanding
- understandingly
- understate