(colloquial) nervous depression

A bright greenish-blue crystalline synthetic pigment from the group of phthalocyanine dyes.

A submarine cave or sinkhole, a roughly circular, steep-walled depression that is typically anoxic below a certain depth.

plural of blue hole

plural of blue box

(organic chemistry) A heterocyclic aromatic chemical compound with many uses in biology and chemistry.

thymolsulphonephthalein

A baby born with cyanosis as a result of a congenital defect

(US politics) A member of the Blue Dog Coalition, founded in 1994, of conservative and moderate members of the Democratic Party.

plural of Blue Dog