Is it 18 times Thanksgiving is said in the bible?

Answer 1

No.

In the King James version

the word - Thanksgiving - appears 28 times

1. Lev 7:12 If he offer it for a thanksgiving, then he shall offer with the sacrifice of thanksgiving unleavened cakes mingled with oil, and unleavened wafers anointed with oil, and cakes mingled with oil, of fine flour, fried.
2. Lev 7:13 Besides the cakes, he shall offer for his offering leavened bread with the sacrifice of thanksgiving of his peace offerings.
3. Lev 7:15 And the flesh of the sacrifice of his peace offerings for thanksgiving shall be eaten the same day that it is offered; he shall not leave any of it until the morning.
4. Lev 22:29 And when ye will offer a sacrifice of thanksgiving unto the LORD, offer it at your own will.
5. Neh 11:17 And Mattaniah the son of Micha, the son of Zabdi, the son of Asaph, was the principal to begin the thanksgiving in prayer: and Bakbukiah the second among his brethren, and Abda the son of Shammua, the son of Galal, the son of Jeduthun.
6. Neh 12:8 Moreover the Levites: Jeshua, Binnui, Kadmiel, Sherebiah, Judah, and Mattaniah, which was over the thanksgiving, he and his brethren.
7. Neh 12:46 For in the days of David and Asaph of old there were chief of the singers, and songs of praise and thanksgiving unto God.
8. Psa 26:7 That I may publish with the voice of thanksgiving, and tell of all thy wondrous works.
9. Psa 50:14 Offer unto God thanksgiving; and pay thy vows unto the most High:
10. Psa 69:30 I will praise the name of God with a song, and will magnify him with thanksgiving.
11. Psa 95:2 Let us come before his presence with thanksgiving, and make a joyful noise unto him with psalms.
12. Psa 100:4 Enter into his gates with thanksgiving, and into his courts with praise: be thankful unto him, and bless his name.
13. Psa 107:22 And let them sacrifice the sacrifices of thanksgiving, and declare his works with rejoicing.
14. Psa 116:17 I will offer to thee the sacrifice of thanksgiving, and will call upon the name of the LORD.
15. Psa 147:7 Sing unto the LORD with thanksgiving; sing praise upon the harp unto our God:
16. Isa 51:3 For the LORD shall comfort Zion: he will comfort all her waste places; and he will make her wilderness like Eden, and her desert like the garden of the LORD; joy and gladness shall be found therein, thanksgiving, and the voice of melody.
17. Jer 30:19 And out of them shall proceed thanksgiving and the voice of them that make merry: and I will multiply them, and they shall not be few; I will also glorify them, and they shall not be small.
18. Amo 4:5 And offer a sacrifice of thanksgiving with leaven, and proclaim and publish the free offerings: for this liketh you, O ye children of Israel, saith the Lord GOD.
19. Jon 2:9 But I will sacrifice unto thee with the voice of thanksgiving; I will pay that that I have vowed. Salvation is of the LORD.
20. 2 Cor 4:15 For all things are for your sakes, that the abundant grace might through the thanksgiving of many redound to the glory of God.
21. 2 Cor 9:11 Being enriched in every thing to all bountifulness, which causeth through us thanksgiving to God.
22. Phi 4:6 Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God.
23. Col 2:7 Rooted and built up in him, and stablished in the faith, as ye have been taught, abounding therein with thanksgiving.
24. Col 4:2 Continue in prayer, and watch in the same with thanksgiving;
25. 1 Tim 4:3 Forbidding to marry, and commanding to abstain from meats, which God hath created to be received with thanksgiving of them which believe and know the truth.
26. 1 Tim 4:4 For every creature of God is good, and nothing to be refused, if it be received with thanksgiving:
27. Rev 7:12 Saying, Amen: Blessing, and glory, and wisdom, and thanksgiving, and honour, and power, and might, be unto our God for ever and ever. Amen.

the word - thansgivings - appears twice

1. Neh 12:27 And at the dedication of the wall of Jerusalem they sought the Levites out of all their places, to bring them to Jerusalem, to keep the dedication with gladness, both with thanksgivings, and with singing, with cymbals, psalteries, and with harps.
2. 2 Cor 9:12 For the administration of this service not only supplieth the want of the saints, but is abundant also by many thanksgivings unto God;