declare, bring (declare, show) glad (good) tidings, preach (the gospel)

“Gospel, the (εύαγγέλιον)” From Concise Bible Dictionary:

“Good news” or “glad tidings.” Everything worthy of this title must come from God. It has not always had the same character. It was good news to Adam and Eve that the Seed of the woman should bruise the head of the serpent. Doubtless they believed it, for Eve said, when Cain was born, “I have gotten a man from the Lord” (Gen. 3:1515And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel. (Genesis 3:15); Gen. 4:11And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the Lord. (Genesis 4:1)). It was good news to Noah (when God made known that He was going to destroy all flesh) that he and his family should be saved in an ark, and that God would establish His covenant with him. Noah believed God, and was preserved (Heb. 11:77By faith Noah, being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house; by the which he condemned the world, and became heir of the righteousness which is by faith. (Hebrews 11:7)). It was good news to Abraham, when called out by God to be blessed by Him, to be told that he should have a son in his old age; that his seed should possess the land, and that in his Seed should all the nations of the earth be blessed (Gal. 3:88And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed. (Galatians 3:8)). Abraham believed God, and it was counted unto him for righteousness (Gen. 15:66And he believed in the Lord; and he counted it to him for righteousness. (Genesis 15:6); Rom. 4:33For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. (Romans 4:3)). It was good news to the Israelites, when slaves to Pharaoh, that God had come down to deliver them by the hand of Moses. They believed the good news, “they bowed their heads and worshipped” (Ex. 4:3131And the people believed: and when they heard that the Lord had visited the children of Israel, and that he had looked upon their affliction, then they bowed their heads and worshipped. (Exodus 4:31)). But this was only a part of the good news to Israel; they were not only to be brought out of Egypt; but to be brought into a “good land and a large, unto a land flowing with milk and honey.” Here alas, many of them failed; though this “gospel,” as it is called in the Epistle to the Hebrews, was preached to them, it did not profit them, because it was not mixed with faith in them: they “entered not in because of unbelief” (Heb. 4:2-62For unto us was the gospel preached, as well as unto them: but the word preached did not profit them, not being mixed with faith in them that heard it. 3For we which have believed do enter into rest, as he said, As I have sworn in my wrath, if they shall enter into my rest: although the works were finished from the foundation of the world. 4For he spake in a certain place of the seventh day on this wise, And God did rest the seventh day from all his works. 5And in this place again, If they shall enter into my rest. 6Seeing therefore it remaineth that some must enter therein, and they to whom it was first preached entered not in because of unbelief: (Hebrews 4:2‑6)).
To Paul was revealed “THE GOSPEL OF THE GLORY,” that God has glorified Christ, and that His glory shines in the face of Him who put away the sins of believers (2 Cor. 4:44In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them. (2 Corinthians 4:4); 1 Tim. 1:1111According to the glorious gospel of the blessed God, which was committed to my trust. (1 Timothy 1:11)). So peculiarly was this committed to Paul that he called it “my gospel” (2 Tim. 2:88Remember that Jesus Christ of the seed of David was raised from the dead according to my gospel: (2 Timothy 2:8)). It embraced more than salvation, great as that is, for he was desirous of making known “the mystery of the gospel,” which separates believers from the first man of the earth, and associates them with Christ glorified in heaven.

“Preaching” From Concise Bible Dictionary:

Solomon in the Ecclesiastes calls himself “the preacher,” and it is said of Noah that he was “a preacher of righteousness.” Paul was appointed a preacher (herald), and it pleased God by “the foolishness of the preaching” to save them that believe. Preaching is still used of God as the means for making known the love of God and the work of Christ.

Strong’s Dictionary of Greek Words:

from 2095 and 32; to announce good news ("evangelize") especially the gospel
KJV Usage:
declare, bring (declare, show) glad (good) tidings, preach (the gospel)