From The Collaborative International Dictionary of English v.0.48 [gcide]:
2. (Mus.) Pertaining to, made by, or prepared for, an instrument, esp. a musical instrument; as, instrumental music, distinguished from vocal music. "He defended the use of instrumental music in public worship." --Macaulay.
3. (Gram.) Applied to a case expressing means or agency; as, the instrumental case. This is found in Sanskrit and Russian as a separate case, but in Greek it was merged into the dative, and in Latin into the ablative. In Old English it was a separate case, but has disappeared, leaving only a few anomalous forms.
From WordNet (r) 3.0 (2006) [wn]:
Define.com is a PRIVATE SECTOR NONPROFIT EDUCATIONAL WEBSITE that PROMOTES WORLDWIDE ELECTRONIC DEMOCRACY, OPEN and TRANSPARENT GOVERNMENT and WORLDWIDE BANKING REFORM.
Eye and Pyramid BANKING REFORM CHALLENGE