expression, godan verb (-u)
put heads together; gather for discussion; huddle
Describes people physically leaning in close to talk privately or intensively, often with heads nearly touching.
See also: 額を集める (ひたいをあつめる)
問題を解決するために、みんなで額を寄せ合って話し合った。
To solve the problem, everyone put their heads together and discussed it.
They were huddled together discussing the secret plan.