The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
ayer-
DEFINITION:
Day, morning. 1a.early, ere, or2, from Old English r, before; b.or2, from Old Norse r, before. Both a and b from Germanic *airiz.2.erst, from Old English rest, earliest, from Germanic (superlative) *airistaz. (Pokorny er- 12.)
r, before; b. or2, from Old Norse 
r, before. Both a and b from Germanic *airiz. 2. erst, from Old English 
er- 12.) 
