A — 1: συμφωνέω
(Strong's #4856 — Verb — sumphoneo — soom-fo-neh'-o )

lit., "to sound together" (sun, "together," phone, "a sound"), i.e., "to be in accord, primarily of musical instruments," is used in the NT of the "agreement" (a) of persons concerning a matter, Matthew 18:19; 20:2,13; Acts 5:9; (b) of the writers of Scripture, Acts 15:15; (c) of things that are said to be congruous in their nature, Luke 5:36 .

2—Corinthians 6:15Luke 15:25
A — 2: συντίθημι
(Strong's #4934 — Verb — suntithemi — soon-tith'-em-ahee )

lit., "to put together" (sun, "with," tithemi, "to put"), in the Middle Voice, means "to make an agreement, or to assent to;" translated "covenanted" in Luke 22:5; "agreed" in John 9:22; Acts 23:20; "assented" in Acts 24:9 .

CONSENT
A — 3: εὐνοέω
(Strong's #2132 — Verb — eunoeo — yoo-no-eh'-o )

lit., "to be well-minded, well-disposed" (eu, "well," nous, "the mind"), is found in Matthew 5:25 , "agree with."

A — 4: πείθω
(Strong's #3982 — Verb — peitho — pi'-tho )

"to persuade," is rendered "agreed" in Acts 5:40 , where the meaning is "they yielded to him." See ASSURE , BELIEVE , CONFIDENT , FRIEND , OBEY , PERSUADE , TRUST , YIELD.

B — 1: γνώμη
(Strong's #1106 — — gnome — gno'-may )

"mind, will," is used with poieo, "to make," in the sense of "to agree," Revelation 17:17 (twice), lit., "to do His mind, and to make one mind;" RV, "to come to one mind," AV, "to agree." See ADVICE , JUDGMENT , MIND , PURPOSE , WILL.

B — 2: συγκατάθεσις
(Strong's #4783 — Verb — sunkatathesis — soong-kat-ath'-es-is )

akin to A, No. 3, occurs in 2—Corinthians 6:16 .

C — 1: ἀσύμφωνος
(Strong's #800 — Adjective — asumphonos — as-oom'-fo-nos )

"inharmonious" (a, negative, sumphonos, "harmonious"), is used in Acts 28:25 , "they agreed not."

C — 2: ἴσος
(Strong's #2470 — Adjective — isos — ee'-sos )

"equal," is used with the verb to be, signifying "to agree," Mark 14:56,59 , lit., "their thought was not equal one with the other." See EQUAL , LIKE , MUCH.

1—Corinthians 7:5Mark 14:70