Here are some palindromes in English:
radar
redivider (one who divides more than once)
repaper
rotator
deified
Finnish holds the world record for the longest palindrome:
saippuakivikauppias (literally, "soap-stone-seller", or in other words, a lye-dealer)
Spanish has
reconocer (the verb, "to recognize")
Danish has
regninger
sneppens
snerrens
Swedish has
rattar ("steering wheels"; also slang for "breasts")
Italian has
onorarono ("to give honor")
avallava ("agree")
French has
serres
essayasse
ressasser ("to repeat the same thing over and over")
I was recently informed about what is supposedly the longest palindrome in German, namely, reliefpfeiler ("pilaster" in English).
Czech has
tahat (pull)
krk (neck)
The best examples in English are
hotshots
beriberi
testes
murmur
tartar
atlatl
Example in French include
chercher
froufrou
rentrent
.
An example in Finnish is valtavalta.
An example in German is
nennen (the verb "to call")
An example in Italian is
restereste ("you would remain").
Some examples in Spanish include
enarenar ("to run aground")
adorador ("worshipper")
arar ("to plow")
Examples in Danish include
farfar
mormor
purpur
Some examples in Dutch include
kerker
tenten
enen
The yellow-headed caracara, a type of bird, has both a common name that is a square, and a Latin name (Milvago chimachima) that is a square.
English has the sort-of-word
shshsh (an admonition to be quiet)
The uncommon word
tratratratra (an extinct lemur from Madagascar)
is a fourth power. Sometimes it is spelled tretretretre.
English has the overlaps
kinnikinnik (a native American tobacco substitute)
alfalfa
entente (taken from French)
In addition to entente, French has
tentent (as in ils tentent, "they are trying")
Dutch has
koekoek
Spanish has
adoradora ("one who adores")
Hungarian has
szeszes
as in the phrase szeszes italok, alcoholic spirits.
For example, the words
tormentor
underfund
ingesting
are all 3/2-powers.
The German word schematische is also a 3/2-power.
The words
entrenchment
entanglement
physiography
educated
keepsake
meantime
reassure
template
usurious
are 4/3-powers.
The words
onion
magma
salsa
verve
are 5/3-powers.
The unfamiliar word uricosuric (increased excretion of uric acid in the urine) is also a 5/3-power.
The words
alchemical
antinomian
hydropathy
meddlesome
phonograph
photograph
repertoire
strategist
are 5/4-powers.
The word brekekekex, devised by Aristophanes to represent frogs croaking, contains a 7/2-power.
The words alfalfa and entente, mentioned previously, are 7/3-powers. The words lophophore and Mississippi contain 7/3-powers.
The word ingoing is a 7/4-power. A 7/4-power in French is cherche.
The word outshout is an 8/5-power.
The word kinnikinnik, mentioned above, is a 9/4-power.
The unusual word tarantara is a 9/5-power. The word fractionation contains a 9/5-power.
The unusual taratantara (a word representing the sound of a trumpet) is an 11/7 power. A more familiar 11/7 power is abracadabra.
English has the Abelian squares
mesosome
reappear
intestines
as well as the less familiar words indenied, notition, vetitive, horseshoer, and meteorometer.
French, however, is positively overflowing with abelian squares. To
list just a few:
resseres (as in "tu resserres", "you make tighter")
entaillaient (as in "ils entaillaient", "they make a deep cut")
entassassent (as in "qu'ils entassassent", subjunctive of "entasser",
"to put in the same place")
entrainerait (conditional of verb "entrainer", "to train" (as for an athletic event))
ressassera (from "ressasser", to repeat the same thing over and over)
retaillerait (conditional of verb "retailler", "to retailor")
taillait (imperfect of "tailler", "to tailor")
tarirait (conditional of "tarir", "to cease flowing")
tenaillaient (imperfect of "tenailler", "to nail down")
trairait (from "traire", "to milk a cow")
German has the very nice 14-letter Abelian square interessierten.
Dutch has entten (grafted); gedoogde (tolerated); gieriger (more miserly); intentie (intention); meenemen (to take along); and overvoer (overfeed).