The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
kei-1
DEFINITION:
To lie; bed, couch; beloved, dear. Oldest form *ei-, becoming *kei- in centum languages. Derivatives include city and cemetery. I. Basic form *kei-.1. Suffixed form *kei-wo-.a.hind3, from Old English hwan, members of a household, from Germanic *hwa-;b.hide3, from Old English hgid,hd, a measure of land (< “household”), from suffixed Germanic form *hwid.2. Suffixed form *kei-wi-.city, civic, civil, from Latin cvis, citizen (< “member of a household”). 3. Suffixed form *kei-liyo-.ceilidh, from Old Irish céle, companion. II. O-grade form *koi-.1. Suffixed form *koi-n-.incunabulum, from Latin cnae, a cradle. 2. Suffixed form *koi-m--.cemetery, from Greek koimn, to put to sleep. III. Suffixed zero-grade form *ki-wo-.Shiva, from Sanskrit iva-, auspicious, dear. (Pokorny 1. ei- 539.)
ei-, becoming *kei- in centum languages. 
wan, members of a household, from Germanic *h
. 2. Suffixed form *kei-wi-. city, civic, civil, from Latin c
-. incunabulum, from Latin c
nae, a cradle. 2. Suffixed form *koi-m-
iva-, auspicious, dear. (Pokorny 1. 
