掛け合う (かけあう)to negotiate (with someone about); to talk over (something with); to tackle someone (about)

to negotiate (with someone about); to talk over (something with); to tackle someone (about)Godan verb with 'u' ending, intransitive verb
to throw on each other; to splash (water) on each other; to pour on each otherGodan verb with 'u' ending, transitive verb

掛け合う, its kanji, and other words that share them.Open this graph

Kanji in 掛け合う

切っ掛けきっかけchance; start
追っ掛けるおっかけるto chase; to run after
仕掛けしかけdevice; contrivance
呼び掛けよびかけcall; appeal
手掛かりてがかりclue; lead
掛け声かけごえshout (of encouragement, etc.); yell (used to time or encourage activity, e.g. "Heave ho!")
呼び掛けるよびかけるto call out to; to hail
掛け金かけきんinstallment; instalment
合意ごうい(coming to an) agreement; consent
問い合わせといあわせenquiry; inquiry
総合そうごうsynthesis; coordination
試合しあいmatch; game
連合れんごうunion; alliance
会合かいごうmeeting; assembly
組合くみあいassociation; union
統合とうごうintegration; unification

See how 掛け合う connects to the rest of Japanese.