group, association
団 centers on a collective unit: a group of people or an organized association. The idea is of something gathered together into a defined whole.
団 is the modern simplified form of 團. The older form combines 囗 (enclosure) with 專, which likely contributed the sound and the idea of something gathered or concentrated. The modern 寸 is a simplification of the inner component.
The outer enclosure 囗 represents a boundary, and inside is 寸, which can be thought of as a hand gathering things. Picture a hand gathering people inside a defined space to form a group or association.
For ダン, imagine a group forming a circle and chanting 'dan, dan, dan' as they unite. The sound 'dan' cues ダン while the group gathers together.
group; party; team
group; mass
futon; Japanese bedding consisting of a mattress and a duvet
army corps; corps
foundation (institution); syndicate; group
baseball team
leader of a group
troupe; theatrical company
bōryokudan; gangster organization (organisation); crime syndicate; yakuza
multi-unit apartments; apartment complex
religious organization; religious organisation
unity; union; solidarity; combination; banding together; teaming up
orchestra; band
joining (a group, team, etc.); enrollment; enrolment
(army) division
zabuton; flat floor cushion used when sitting or kneeling; usu. rectangular
mass; lump; clod; clump
brigade
leaving (a group, team, etc.)
group member
body; group; party; gang; troupe; troop
uchiwa; type of traditional Japanese handheld fan
public corporation
futon (laid on the floor); (Japanese) mattress; underquilt; sleeping mat
corporation; foundation
symphony orchestra
chorus group; choir
Japan International Cooperation Agency (1974); JICA
local public body; local government
auxiliary organization (organisation); extra-departmental body; fringe organization
National Space Development Agency; NASDA
corporate juridical person; incorporated body; corporation
orchestra
incorporated foundation; juridical foundation
young persons' association