The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
ad-
DEFINITION:
To, near, at. 1a.at1; atone, twit, from Old English æt, near, by, at; b.ado, from Old Norse at. Both a and b from Germanic *at.2.ad-, –ad; adjuvant, aid, amount, paramount, from Latin ad,ad-, to, toward. 3. Celtic *ad-, to, at, in compound *to-ad-ni-sed- (see sed-). (Pokorny 1. ad- 3.)
