赤

great spotted woodpecker (Dendrocopos major)

Astronomy

red dwarf

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

tropical fire ant (Solenopsis geminata)

Asian hornet (Vespa velutina); Asian predatory wasp

Medicine

shigellosis; bacillary dysentery

erythrophobia; fear of blushing

Noun or verb acting prenominally

florid; ruddy

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

Biology

Red Queen hypothesis (of evolutionary biology)

Equatorial Guinea

red letter style; cutesy fashion style named after fashion magazines featuring it (whose cover titles are printed in red or pink)

Organization name

Red Army Faction; Baader-Meinhof Group

red cabbage

Hanafuda

scoring combination consisting of the January, February and March 5-point cards

Red Crescent Society

Proverb

the grass is always greener on the other side of the fence; the neighbour's flowers are redder

red kidney bean

scalloped hammerhead (Sphyrna lewini); bronze hammerhead shark

equatorial radius

Medicine

sickle cell anemia (anaemia); sickle cell disease

doldrums

trade deficit with Japan

Scots pine (Pinus sylvestris)