The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
swer-
DEFINITION:
To speak, talk. O-grade form *swor-.a.swear, from Old English swerian, to swear, proclaim, from Germanic *swarjan; b.answer, from Old English andswaru, answer, from Germanic *and-swar, “a swearing against,” “rebuttal” (*andi-, against; see ant-). (Pokorny 1. ser- 1049.)
, “a swearing against,” “rebuttal” (*andi-, against; see ant-). (Pokorny 1. s
er- 1049.) 
