“HARDHAT” is a valid word. — 14 points Scrabble

hardnot easy; requiring great physical or mental effort to accomplish or comprehend or endure
dataa collection of facts from which conclusions may be drawn
hath
hartUnited States playwright who collaborated with George S. Kaufman (1904-1961)
darta small narrow pointed missile that is thrown or shot
haha
drat
rath
tradtraditional jazz as revived in the 1950s
haar
tahr

hadhave or possess, either in a concrete or an abstract sense
artthe products of human creativity; works of art collectively
aahexpress admiration and pleasure by uttering `ooh' or `aah'
hatheaddress that protects the head from bad weather; has shaped crown and usually a brim
ratany of various long-tailed rodents similar to but larger than a mouse
aha
hah
tada slight amount or degree of difference
tarany of various dark heavy viscid substances obtained as a residue
rada unit of absorbed ionizing radiation equal to 100 ergs per gram of irradiated material
dahthe longer of the two telegraphic signals used in Morse code
rah

ata highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium
ah
ha(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day
ada public promotion of some product or service
taa hard grey lustrous metallic element that is highly resistant to corrosion; occurs in niobite and fergusonite and tantalite
ara colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere
aaa dry form of lava resembling clinkers

HARDHAT