rap这个单词的由来是什么,它的具体意思又是什么.

rap
[rAp]
n.
叩击, 轻拍, 轻敲, 斥责
vt.
敲, 拍, 打, 厉声说出, 斥责, 使着迷
vi.
敲击, 交谈
abbr.
[军] Rocket Assisted Projectile, 火箭助推炮弹

RAP
=Read Alphanumerically Paper[计]读字母数字纸带

rap
rap 1
AHD:[r²p]
D.J.[r#p]
K.K.[r#p]
v.（动词）
rapped， rap.ping， raps
v.tr.（及物动词）
To hit sharply and swiftly; strike:
敲击：快速极重地打击；狠狠一击：
rapped the table with his fist.
用拳头重击桌子
To utter sharply:
厉声说出：
rap out a complaint.
尖锐地说出埋怨之词
To criticize or blame.
批评，责骂
v.intr.（不及物动词）
To strike a quick, light blow:
轻敲：快速、轻轻地叩击：
rapped on the door.
敲门
n.（名词）
A quick, light blow or knock.
轻敲，轻叩：快速、轻轻的打击或敲打
A knocking or tapping sound.
敲击声：敲击或叩击发出的声音
Slang
【俚语】
A reprimand.
批评，指责
A sentence to serve time in prison.
有期徒刑：在狱中服刑的判决
Slang A negative quality or characteristic associated with a person or an