ETYM Gael. sluagh-ghairm, i.e., an army cry; sluagh army + gairm a call, calling.
1. A phrase associated with a political cause or movement.
2. Any rallying cry.
3. Catchphrase of a type commonly used in advertising and politics. A slogan needs to be short and memorable. Wordplay and puns are often used in slogans (“Gotta lotta bottle”, “Go to work on an egg”).