The actual word "thanksgiving" or its plural is found thirty times in the King James Bible, nine of which occur in the New Testament (2Corinthians 4:15, 9:11 - 12, Philippians 4:6, Colossians 2:7, 4:2, 1Timothy 4:3 - 4, Revelation 7:12). Of these nine occurrences, the apostle Paul refers to thanksgiving toward God eight times while John refers to it only once.
The Old Testament use of the word thanksgiving (in the majority of cases) comes from the Hebrew todah (Strong's Concordance #H8426), which means the extension of the hand. Brown-Driver-Briggs' Hebrew Definitions states this original language word means confession, praise or thanksgiving made toward God which can take the form of offering praises, singing hymns and other songs, and so on. In every New Testament case, the word thanksgiving comes from the Greek eucharistia (Strong's #G2169), which means gratitude, giving thanks, or conveying gratefulness to God as an act of worship.
An excellent example of praising the Eternal for his manifold blessings is found in the book of Revelation. It occurs after all those who are martyred in the Great Tribulation period are resurrected from the dead and made to stand before God's throne (Revelation 7:9, 13 - 14). After these righteous people shout, "The salvation of our God has come" (verse 10, HBFV), all others in heaven (e.g. righteous angels, twenty-four spiritual elders, etc.) bow before the Almighty and say, "Blessing, and glory, and wisdom, and thanksgiving, and honor, and power and strength be to our God into the ages of eternity . . ." (verse 12, HBFV).
BibleStudy.org is sometimes asked what would be a good prayer to offer before partaking of a meal or on a special holiday like Thanksgiving. These, like most other kinds of prayers, should always be given from the heart. They should not be merely reciting something that is well known and memorized like the Lord's Prayer.
One suggested prayer of thanks would be to first acknowledging God as our righteous and loving Father. Next, it would be appropriate to thank him for graciously allowing us to have a relationship with him and for bringing safely together those in attendance. This could be followed by thanking him for making possible all the blessings that have been received, including the meal that will be eaten. The prayer should be closed in Jesus' name (John 16:23 - 24, 26). Biblical examples, for further study, of thanking God can be found in Exodus 15, Psalms 100, 103, 106 and 107, Luke 1:46 - 55, 2:13 - 14, Romans 11:33 - 36, and Revelation 5:8 - 14, 7:9 - 12, 11:16 - 18.
Thanksgiving to our great Father should be offered every time we pray (Ephesians 5:20, Philippians 4:6, 1Thessalonians 5:18). We should always acknowledge our physical, as well as spiritual, blessings we receive from his hand (Colossians 1:12, 1Timothy 4:3 - 4). Thanking God for his loving care and generosity towards us is always the right thing to do because He justly deserves it.