from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A word, phrase, verse, or sentence that reads the same backward or forward. For example: A man, a plan, a canal, Panama!
- n. A segment of double-stranded DNA in which the nucleotide sequence of one strand reads in reverse order to that of the complementary strand.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A word, phrase, number or any other sequence of units which has the property of reading the same forwards as it does backwards, character for character, sometimes disregarding punctuation, capitalization and diacritics.
- n. A poetic form in which the sequence of words reads the same in either direction.
- n. A stretch of DNA in which the sequence of nucleotides on one strand are in the reverse order to that of the complementary strand
from the GNU version of the Collaborative International Dictionary of English
- n. A word, verse, or sentence, that is the same when read backward or forward
from The Century Dictionary and Cyclopedia
- n. A word, verse, or sentence that reads the same either from left to right or from right to left. The English language has few palindromes. Examples are—“Madam, I'm Adam” (supposed speech of Adam to Eve); “lewd did I live & evil I did dwel” (John Taylor).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a word or phrase that reads the same backward as forward
From Greek palindromos, running back again, recurring : palin, again; see kwel-1 in Indo-European roots + dromos, a running.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Ancient Greek παλίνδρομος (palindromos, "running back again"), from πάλιν (palin, "back, again, back again") + δρόμος (dromos, "running, race, racecourse") (Wiktionary)