ACCEDED, CABBAGE, BAGGAGE, DEFACED, EFFACED, DECEDED, DEEDEED, DEFADED, DEGAGEE, GEAGGED, and FEEDBAG are seven-letter words which can be played on a musical instrument. CABBAGED, DEBAGGED, and BAGGAGED are eight-letter words.
The following words in the on-line Scrabble dictionary have symmetrically distributed letters: WIZARD, HOVELS, BEVY, GIRT, GRIT, IZAR, LEVO, TRIG, VOLE, WOLD, BY, LO, and SH. There is also ZYBA (a town in Kansas), which was named by taking the last two letters and the first two letters of the alphabet. POLK is the only last name of a U. S. President with symmetrically distributed letters. "Symmetrically distributed letters" means that, for example, in BEVY the B and Y are equidistant from the center, as are E and V.
The following ten-letter words have one occurrence of one letter, two occurrences of another letter, three occurrences of another letter, and four occurrences of another letter: COEFFEOFFE, REMEMBERER, SERENENESS, SHAHANSHAH, SLEEVELESS, TENTRETENE. The list of six-letter words with a similar property is very long, but it includes these common words: BANANA, COCOON, DEEMED, DOODAD, GOOGOL HORROR, MAMMAL, PEPPER, POWWOW, TATTOO.
ASTHMA begins and ends with a vowel and has no other vowels in between. Some less common words of six or more letters with this property are ISTHMI (alternate plural of isthmus), APHTHA (OSPD3), ELTCHI (SOWPODS), ORMSBY (name of several towns in the U. S.), ACHCHA (a S. Asian expression meaning "is that so"), ANDHRA (an Indian State), ANGSTY (adjective of angst), ORCHHA (an Indian State), ORPHNE (Greek nymph in Hades), ARCHLY, ICHTHY, and ARCHSPY. There are also these obsolete or obscure words from the OED2: ARMTHE, ERMTHE, ARCTLY, ARGHLY, ENGHLE, ESSSSE, ERSHRY, ERSTLY, IRSCHE, UNCKLE, USSCHA, and USSCHO.
Some two-syllable words which become one-syllable words by adding a letter or letters are: AGUE/PLAGUE, AGUE/VAGUE, AVE/CAVE, AVE/HAVE, RUGGED/SHRUGGED, AGED/RAGED, AGED/STAGED, BOA/BOAT, OLE,SOLE OLE/WHOLE, RAGGED/DRAGGED, NAKED/SNAKED, SOUR/SOURCE, WINGÉD/TWINGED.
Some common words which change from one to three syllables upon the addition of just one letter are: ARE/AREA, CAME/CAMEO, CRIME/CRIMEA, GAPE/AGAPE, HOSE/HOSEA, JUDE/JUDEA, LIEN/ALIEN, OLE/OLEO, RODE/RODEO, ROME/ROMEO, SMILE/SIMILE and WHINE/WAHINE.
Some words which, when spelled backwards, form other words are: AMAROID/DIORAMA, ANIMAL/LAMINA, DEIFIER/REIFIED, DELIVER/REVILED, DENIER/REINED, DENIES/SEINED, DENNIS/SINNED, DESSERT/TRESSED, DESSERTS/STRESSED, DIAPER/REPAID, DRAWER/REWARD, ECITON/NOTICE, ELIDES/SEDILE, ENAMOR/ROMANE, GATEMAN/NAMETAG, LEPER/REPEL, LIVED/DEVIL, LOOTER/RETOOL, MULLAHS/SHALLUM, PACER/RECAP, PARTS/STRAP, PILFER/REFLIP, PUPILS/SLIPUP, REDIPS/SPIDER, REDRAW/WARDER, REFLOW/WOLFER, REGAL/LAGER, REKNIT/TINKER, REKNITS/STINKER, RECAPS/SPACER, REVOTES/SETOVER, SATRAPS/SPARTAS, SKUA/AUKS, SLEETS/STEELS, SLOOPS/SPOOLS, SNOOPS/SPOONS, SPORTS/STROPS, STRAW/WARTS
ALMS is a word with no singular form. Other words with no singular form or a rarely used singular form are: AGENDA, IDES, BRACES, CATTLE, CLOTHES, DIBS, EAVES, MARGINALIA, PANTS, PLIERS, SCISSORS, SHORTS, and TROUSERS (although there is "trouser leg").
CORPS has the plural spelled the same way as the singular but pronounced differently. Other such words are CHASSIS, BOURGEOIS, RENDEZVOUS, PINCE-NEZ, FAUX PAS, GARDEBRAS, PRÉCIS.
CARES, LARGES, TIMELINES and PRINCES are examples of plural words that become singular words (caress, largess, timeliness, and princess) with another added S. Some other words which become singular words with the addition of an S are: abbes, abys, adventures, bas, bos, bras, bulgines, chapes, cites, cosines, deadlines, esquires, fras, gamines, gaus, glassines, gues, hos, kavas, kos, las, los, lownes, marques, mas, millionaires, mis, moras, mos, multimillionaires, nervines, ogres, pas, pis, pos, posses, prelates, pros, sagenes, saltines, shines, sightlines, squires, tartines, tas, tyrranes, usures, zebras, camas, careles, carles, cos, discus, dos, dures, es, footles, garbles, handles, his, homines, hurtles, inkles, kermes, kindles, koumis, koumys, mes, mus, needles, poses, princes, pus, restles, rumples, rustles, tackles, tailles, treadles, tres, wattles, windles, wis, amas, amis, as, asses, bibles, bus.
FOLK and FOLKS are both plurals, with no singular form.
KINE (an archaic plural of COW) qualifies as a plural that shares no letters in common with its singular. Others are I/WE, ME/US. If one overlooks the change in case, then US can be considered a plural of I, in which case it reverses the common method pluralizing certain words by changing -us to –i.
SERIES is a singular word ending in S, but its plural is identical. Others are SPECIES, CONGERIES, SHAMBLES, KUDOS and PREMISES.
[In older dictionaries, KUDOS (pronounced koo-doss) was a singular word. However, widespread mispronunciation of the word has led some modern dictionaries to list KUDO as the singular form created by back-formation.
HAIR is a word that as a singular suggests more than its plural.
JINNI is a singular form that becomes shorter when pluralized to JINN.