Jizz

(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/

Jizz

[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)

Jizz

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

Jizz

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

jizz

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

Jizz

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
No exact match found