So there may be association in business without intimacy or friendship. As regards studies, pursuits, etc., acquaintance is less than familiarity, which supposes minute knowledge of particulars, arising often from long experience or association.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

union It is improper to impose sanctions upon the union.
alliance Algeria has good relations with the NATO alliance.
federation Tatarstan is a republic of the Russian Federation.
affiliation Tom doesn't vote based on political affiliation.
company We need a new leader to pull our company together.
connection Yanni and Skura developed an immediate connection.

Popularity over time

Word	1850 → 2019	Trend
association		falling
union		falling
alliance		steady
federation		falling
affiliation		steady
company		steady

Use in printed books, per decade from 1850 to 2019.

By length

3 letters: tie¹
4 letters: body², club¹, band¹, bond¹
5 letters: union², guild¹
6 letters: league¹, kongsi
7 letters: company³, college², society⁴, concert², linkage²
8 letters: alliance³, relation³
9 letters: community⁴, syndicate³, collusion³
10 letters: connection³, membership³, friendship², federation⁴, fellowship³, fraternity⁴
11 letters: combination⁴, partnership³, brotherhood³, conjunction³, affiliation⁵, confederacy⁵, comradeship
13 letters: participation⁵, collaboration⁵, confederation⁵, incorporation⁵, confraternity

The small number after each word is its number of syllables (body² = 2 syllables).

In other languages

Français: association
Italiano: associazione
Español: asociación
Deutsch: Assoziation
Català: associació