One thousand contains the letter A, but none of the words from one to nine hundred ninety-nine has an A.
FOUR has four letters; no other number has this property in English such that the number of letters in the name equals the number.
Some words with horizontal symmetry (they reflect themselves across a horizontal line) are: BEDECKED, BOOHOOED, CEBID (a type of monkey), CHECKBOOK, CHOICE, CODEBOOK, COOKBOOK, DECIDED, DIOXIDE, DOBCHICK, EXCEEDED, HIDE, HOODOOED, ICEBOX, KEBOBBED, OBOE, OKEECHOBEE.
Some words with vertical symmetry are MOM, WOW, OTTO, MAAM, MA'AM, TOOT, AHA, AA, AHA, AIA, AMA, AVA, AWA, HAH, HOH, HUH, MAM, MIM, MM, MUM, OHO, OO, OXO, TAT, TIT, TOT, TUT, UTU, VAV, WAW.
