赤

Japanese mallotus (Mallotus japonicus)

mallotus bark (herbal medicine)

great spotted woodpecker (Dendrocopos major)

Astronomy

red dwarf

vermillion stick; red ink

loss-making line (railway, bus, etc.); unprofitable route

infrared

last train (of the day)

northern sea nettle (Chrysaora melanaster)

right ascension

tropical fire ant (Solenopsis geminata)

blackthroat seaperch (Doederleinia berycoides); rosy seabass

loggerhead turtle (Caretta caretta)

bloodworm (Halla okudai)

red mite (Trombicula akamushi); chigger mite; harvest mite

Abbreviation

Akasaka Prince Hotel

erythrophobia; fear of blushing

Noun or verb acting prenominally

florid; ruddy

bare feet

Mahjong

red dora; red suited tile that doubles the score of any hand (usu. a five of each suit)

extremely indigent; extremely poor; in dire poverty; as poor as a church mouse

Abbreviation; Medicine

erythrocyte sedimentation rate; ESR

Biology

Red Queen hypothesis (of evolutionary biology)

pond slider (Trachemys scripta); red-eared slider turtle

Equatorial Guinea

anko-coated mochi (from Ise, Mie pref.)