To pass the winter in a dormant or torpid state of excessive masturbation.
as a verb:
"All he did last winter was hiberbate."
as a noun:
"This smallness of this town is conducive to hiberbation."
"I envy that particular individual for his consummate position as an avid hiberbator."
Someone who ignores all their other friends when they are masturbating for extended periods of time.
Jeff never wants to come out with us, because all he does is hiberbate!