palindrome
noun
pal·in·drome ˈpa-lən-ˌdrōm 
: a word, verse, or sentence (such as "Able was I ere I saw Elba") or a number (such as 1881) that reads the same backward or forward
palindromic
ˌpa-lən-ˈdrō-mik
adjective -ˈdrä-
palindromist
ˈpa-lən-ˌdrō-mist
noun 
Did you know?
Palindrome comes from Greek palindromos, meaning "running back again," which itself is from palin ("back," "again") and dramein ("to run"). Nowadays, we appreciate a clever palindrome—such as "Drab as a fool, aloof as a bard" or "A man, a plan, a canal: Panama"—or even a simple one like "race car," but in the past palindromes were more than just smart wordplay. Some folks thought they were magical, and they carved them on walls or amulets for protection.
Example Sentences
The word “dad” and the number “1881” are palindromes.
Recent Examples on the Web Thursday marks an eight-digit palindrome, which occurs only 12 times this century. 
Jay Cannon, USA TODAY, 2 Dec. 2021 The next date to feature a five-digit palindrome with only one number will occur next century, on Jan. 11, 2111, or 1/11/11. Joseph De Avila, WSJ, 22 Feb. 2022 The ultimate palindrome will occur at 2:22 a.m. or p.m., or at 22:22 military time. Kelly Tyko, USA TODAY, 22 Feb. 2022 The date is also a palindrome, which is read the same way forward and backward. Charmaine Patterson, PEOPLE.com, 24 Feb. 2022 The last palindrome date of special notice also occurred last year on 1/21/21, for being the 21st day of the 21st year of the 21st century. Zachary Smith, cleveland, 21 Feb. 2022 Palindrome-loving gamblers will have another opportunity to strike it rich in about 11 years, as Thursday, March 3, 2033, marks our next single-number palindrome date. Lauren Wethington, Detroit Free Press, 23 Feb. 2022 On her Instagram Story Tuesday, the 37-year-old Good American co-founder reshared a post about this year's special palindrome date, 2/22/22. Dory Jackson, PEOPLE.com, 23 Feb. 2022 It’s a palindrome date, meaning it can be read the same forward and backward. Leada Gore | Lgore@al.com, al, 22 Feb. 2022 See More
Jay Cannon, USA TODAY, 2 Dec. 2021 The next date to feature a five-digit palindrome with only one number will occur next century, on Jan. 11, 2111, or 1/11/11. Joseph De Avila, WSJ, 22 Feb. 2022 The ultimate palindrome will occur at 2:22 a.m. or p.m., or at 22:22 military time. Kelly Tyko, USA TODAY, 22 Feb. 2022 The date is also a palindrome, which is read the same way forward and backward. Charmaine Patterson, PEOPLE.com, 24 Feb. 2022 The last palindrome date of special notice also occurred last year on 1/21/21, for being the 21st day of the 21st year of the 21st century. Zachary Smith, cleveland, 21 Feb. 2022 Palindrome-loving gamblers will have another opportunity to strike it rich in about 11 years, as Thursday, March 3, 2033, marks our next single-number palindrome date. Lauren Wethington, Detroit Free Press, 23 Feb. 2022 On her Instagram Story Tuesday, the 37-year-old Good American co-founder reshared a post about this year's special palindrome date, 2/22/22. Dory Jackson, PEOPLE.com, 23 Feb. 2022 It’s a palindrome date, meaning it can be read the same forward and backward. Leada Gore | Lgore@al.com, al, 22 Feb. 2022 See More Word History
Etymology
Greek palindromos running back again, from palin back, again + dramein to run; akin to Greek polos axis, pole — more at pole, dromedary
First Known Use
circa 1637, in the meaning defined above
Kids Definition
palindrome
noun
pal·in·drome ˈpa-lən-ˌdrōm
: a word, phrase, sentence, or number that reads the same backward or forward
"Step on no pets" is a palindrome.
Medical Definition
palindrome
noun
pal·in·drome ˈpal-ən-ˌdrōm
: a palindromic sequence of DNA