quword
趣词
Word Origins Dictionary
A
B
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D
E
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H
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a.m.
[a.m. 词源字典]
in reference to hours, 1762, abbreviation of Latin
ante meridiem
"before noon."
[a.m. etymology, a.m. origin, 英语词源]
A.M.
also
AM
, type of radio wave broadcast, 1921, abbreviation of
amplitude
modulation
.