Lexical Definition

‎σύμβουλος‎ sýmboulos (soom'-boo-los) counselor G:N-M
from ‎σύν‎ and ‎βουλή‎

counsellor.

Usage: 6 forms in 19 verses
Form Translated As     In Verse(s)
σύμβουλοσ a counselor LXX.1Chr.27.32
counselor LXX.2Sam.8.18LXX.1Chr.27.33LXX.Isa.9.6LXX.Isa.40.13Rom.11.34
his counselor LXX.2Chr.22.3
σύμβουλον counselor LXX.2Sam.15.12LXX.2Chr.25.16LXX.Isa.3.3
σύμβουλοι counselors LXX.2Chr.22.4LXX.Ezra.7.15LXX.Isa.19.11
his counselors LXX.Ezra.8.25
σύμβουλοί your counselors LXX.Ezek.27.27
συμβούλων counselors LXX.Ezra.7.14
his counselors LXX.Ezra.7.28
συμβούλουσ counselors LXX.Ezra.4.5
your counselors LXX.Isa.1.26

Abbott-Smith

σύμβουλος, -ου, ὁ (< σύν, βουλή), [in LXX forיוֺעֵץand cogn. forms ;]
a counsellor, adviser: Ro 11:34 (LXX).†

Abbott-Smith References

Book Refs
Romans 11:34

Liddell-Scott-Jones

σύμβουλος-ος, ,

adviser, counsellor, in public or private affairs, [NT+5th c.BC+]: with genitive person, one's adviser, [σύμβουλοςοι πέρι 4th-5th c.BC: Aeschylus Tragicus “Choephori” 86, compare 5th-6th c.BC: Plato Philosophus “Protagoras” 319b; ὑπέρ τινος 5th-6th c.BC: Isocrates Orator 1.35: ξύμβουλός εἰμι,= συμβουλεύω">Refs 5th c.BC+], advise, with infinitive, [Refs 5th c.BC+]

__II as a title,
__II.1 at Athens, the θεσμοθέται were empowered to appoint σύμβουλοςοι (perhaps in a private capacity), [Refs]
__II.2 at Sparta, a board of advisers sent with the general, [Refs 5th c.BC+]
__II.3 officers at Thurii, [Refs 4th c.BC+]
__II.4 = Latin legatus, [Refs 2nd c.BC+]; also used to explanation Latin con-sul, [Refs 1st c.BC+]

LSJ Scripture Refs: Rom.11.34