junior partner
noun[C]
ukusamemberof agroupofpeople,companies,countries, etc. that isinvolvedincontrollingsomething but that has lessinfluenceorexperiencethanothersin thegroup:
Severalforeigncompanieswereinvitedtostayon asjuniorpartnersin thepetroleumfirm.
Thegovernmentcollapsedafter thejuniorpartnerin thecoalitionpulledout.
Compare
senior partner
 This example is from Wikipedia and may be reused under a CC BY-SA license.
This example is from Wikipedia and may be reused under a CC BY-SA license.