Definition of jizzes:
(n) :
(vulgar, slang) Male ejaculate; sperm, semen.
(v) :
(intransitive, slang) To ejaculate; to eject semen.
(v) :
(transitive, slang) To ejaculate on, over, or into; to cover in semen.
(n) :
(ornithology, birdwatching) The physical and behavioural characteristics of a bird that enable it to be immediately recognised by an experienced birder as a certain type of bird, especially to family or genus level.