noun
one party; one faction; one clique
Refers to a single political party, faction, or group as one side among others. Often used in political compounds and phrases such as 一党支配, 一党独裁, and 一党一派.
その国では長く一党支配が続いた。
One-party rule continued in that country for a long time.
この法案は一党だけでは通せない。
This bill cannot be passed by one party alone.
Reporting must not be biased toward any one party or faction.
政党 is the general word for a political party; 一党 emphasizes one party as a single side or unit.
派閥 means a faction within a party, organization, or group; 一党 can refer to one party or faction as a whole.
一党独裁 is a compound meaning one-party dictatorship; 一党 by itself only means the one party or faction.
A transparent Sino-Japanese compound: 一 means 'one' and 党 means 'party, faction, or group.'