動(dòng)詞 wigwag:

1. send a signal by waving a flag or a light according to a certain code
2. signal by or as if by a flag or light waved according to a code

wig.wag

v.（動(dòng)詞）
wig.wagged,wig.wag.ging,wig.wags
v.intr.（不及物動(dòng)詞）
To move back and forth; wag steadily or rhythmically:
搖動(dòng)，搖擺：前后移動(dòng)；穩(wěn)定而有節(jié)奏地?fù)u擺：
例句：
watched the pendulum wigwag.
觀察鐘擺的擺動(dòng)

To signal by waving an upraised arm, a flag, or a light, especially in accordance with a code.
打旗語(yǔ)，用燈光發(fā)信號(hào)：通過(guò)搖動(dòng)舉起的手臂、旗子或燈來(lái)示意，尤指按符號(hào)示意
v.tr.（及物動(dòng)詞）
To move (something) back and forth steadily or rhythmically.
搖動(dòng)：前后穩(wěn)定而有節(jié)奏地移動(dòng)（某物）
To convey (a message or signal) by waving an upraised arm, a flag, or a light.
打旗語(yǔ)發(fā)信號(hào)，用燈光發(fā)信號(hào)：通過(guò)搖擺舉起的手臂、旗子或燈來(lái)傳達(dá)（信息或記號(hào)）
n.（名詞）
The act or practice of wigwagging.
搖動(dòng)，搖擺：搖擺的動(dòng)作或作法
A message sent by this method.
旗語(yǔ)信號(hào)，燈光信號(hào)：通過(guò)旗語(yǔ)、燈語(yǔ)或手勢(shì)傳達(dá)的消息

來(lái)源：
Dialectal wig [to move]
方言 wig [移動(dòng)]
wag
wag

【引伸】
wig.wag.ger
n.（名詞）