According to http://www.Biology-online.org,
The act of sowing (of seeds in the ground or, figuratively, of germs in the body or ideas in the mind, etc.).The introduction of semen into the genital tract of a female.insemination
deposit of seminal Fluid within the vagina, normally during coitus.
Why this word?
I was looking at a forwarded picture of a group of men pointing something at the horse.
The title of the pic was insemination.
I was like... asking my colleague... what's that!??
Now I know, they are trying to fertilize the horse with one big load of thing.