soundingのようなどんな単語でも探してください。
 
1.
A form of greeting someone without using words.
Like a normal nod but insteading of stating with your head going down, it goes up first.

Lads normally do it instead of waving.
"Josh just gave me an upnod while i made a tit of myself by waving" :(
EJMCによって 2009年02月14日(土)
 
2.
The silent sign of respect
No words were spoken, just a slight upnod was all that was needed. upnod.com
jhickenによって 2010年03月25日(木)
 
3.
The act of raising one's chin as an acknowledgement of another person. Significant in that it exposes the throat, long thought a point of vulnerability.
Phil greeted Fred with a wry grin and an up nod in silent greeting. See also jock nod.
Doctor Psychoによって 2014年09月06日(土)