“RIDGIER” is a valid word. — 9 points Scrabble

ridgea long narrow natural elevation or striation
ridera traveler who actively rides an animal (as a horse or camel)
rigidincapable of or resistant to bending
driera substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)
dirgea song or hymn of mourning composed or performed as a memorial to a dead person
rerig
gride
direrfraught with extreme danger; nearly hopeless

diea small cube with 1 to 6 spots on the six faces; used in gambling to generate random numbers
redred color or pigment; the chromatic color resembling the hue of blood
ridrelieve from
digthe site of an archeological exploration
riggear (including necessary machinery) for a particular enterprise
reg
errto make a mistake or be incorrect
rei
ged
gie
irea strong emotion; a feeling that is oriented toward some real or supposed grievance
gid
erga cgs unit of work or energy; the work done by a force of one dyne acting over a distance of one centimeter

era trivalent metallic element of the rare earth group; occurs with yttrium
dea Mid-Atlantic state; one of the original 13 colonies
edimpotence resulting from a man's inability to have or maintain an erection of his penis
rea rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
ida state in the Rocky Mountains

RIDGIER