
1) Slang for semen 2) Stuff formed in balls, partly
Found on
https://www.crosswordclues.com/clue/jizz

The sum total of all the characteristics that make a bird species unique. The jizz includes their shape, color, voice, behaviors, etc.
Found on
http://birding-world.com/glossary-birdwatching-slang/
(or Gizz) the overall impression given by the general shape, movement, behaviour, etc., of a species rather than any particular feature. Experienced birders can often identify species, even with only fleeting or distant views, on jizz alone. It generally accepted that the term is slang from the second world war where planes were identified o...
Found on
http://birding101.co.za/newbirder/birding-terms/
[birding] Jizz is a term used by birders to describe the overall impression or appearance of a bird garnered from such features as shape, posture, flying style or other habitual movements, size and colouration combined with voice, habitat and location. Sean Dooley described jizz as `the indefinable quality of a particular species, the `vibe...
Found on
http://en.wikipedia.org/wiki/Jizz_(birding)

Essence or striking characteristics of a species;
Found on
http://www.encyclo.co.uk/local/22219

The over-all character of a bird, its holistic impression that aids recognition in the field. The term is derived from fighter pilot’s acronym, “GISS”, which stands for General Impression Size and Shape. This term is important for birders in learning to identify a species immediately after a quick glance.
Found on
http://www.kuwaitbirds.org/birding/glossary

semen
Found on
http://www.noslang.com/dictionary/j/

Jizz is slang for semen.
Found on
http://www.probertencyclopaedia.com/browse/ZJ.HTM

Birding term for a quick impression of a bird's major features. Jizz harkens back to the “general impression of size and shape” (G. I. S. S.) that British observers used during World War II to distinguish between enemy and friendly aircraft.
Found on
https://academy.allaboutbirds.org/bird-academys-a-to-z-glossary-of-bird-ter

Essence or striking characteristics of a species
Found on
https://birds.iitk.ac.in/glossary?page=110

The overall impression of a bird based on size, shape, colour, (sometimes plumage), posture, flight, movements, song and call, habitat, and location, awareness of jizz provides for a positive ID even in the face of BVD.
Found on
https://www.sciencebase.com/science-blog/birding-glossary.html
No exact match found.