1) A channel dug in the ground where men go to deposit their seamen.

2) A women who's 'channel' is where men go to deposit their seamen.

3) A man who's 'channel' is where men go to deposit their seamen

4) A situation that arose in WWI when the entiraty of ones unit was homosexual.
"Dude I have all of this sperm but no where to leave it, what should I do?"
"Why dont you leave it in Nicks mum she's a sperm trench"

or

As the Huns approached the entrenched British position they could see that the British were flying a rainbow flag and the soldiers were dancing to the YMCA. The Germans realised that they were approahcing a sperm trench.
by Trampon October 28, 2006
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