an egg (of a bird, fish, or insect); a female reproductive cell (ovum)

(colloquial) testicles; the male reproductive organ

(slang) an expletive used for emphasis or to express frustration, similar to "fucking"; also an archaic term for the penis

(slang) nothing; of no use; useless, often in the phrase 有个卵用 yǒu​gè​luǎn​yòng