Jizz Shamrock 

When you blow your load on your chick and mix it with green food coloring in the spirit of St. Patrick's Day

I woke up this morning to my boyfriend giving me Jizz Shamrock face painting. Complete with green food coloring and sprinkles.

Jizz Shamrock by BlarneyBone March 31, 2011

Shamrock Shake 

An Irish handjob

I met a drunk Irish lass on St. Patrick's Day, and she gave me a shamrock shake.

Shamrock Shake by Lordwindowlicker August 5, 2012

Shamrock Shame 

The time of which you have consumed too many Shamrock Shakes from McDonalds.

Bob: Dude, I have gained five pounds in the last month! I must have had too many Shamrock Shakes.
Joe: You have Shamrock Shame.

Shamrock Shame by bahhahahahaaa March 6, 2011

silver shamrock 

Overused internet saying, started by the Clock Crew. It's meant to be a substitute for LOL, because Dwarfinator got banned for saying LOL on the NG boards. Taken from a costume company in the Halloween movies.

Silver Shamrock, that's awesome!

silver shamrock by Dodger of Zion January 12, 2004

shamrock 

it's an irish penis

check out that shamrock!

shamrock by serpeco May 28, 2001

shamrock 

Verb.

(1) To screw someone over; scam.

(2) To inflict severe injury upon someone as leverage to facilitate the extortion of money.

"Shamrock" is most frequently encountered in the passive, as in, "you have been shamrocked." (Origin: Shamrock Towing, a notoriously unethical business in the greater Columbus, Ohio area, ca. 1957)

(1) After paying $115 for the predatory towing of his car, Willis figured out he'd been shamrocked and called an attorney.

(2) "You didn't pay Vinnie your protection this month?! Buddy, you are sooo shamrocked!"

shamrock by Carl Willis April 27, 2004

Shamrock Shake 

When performing a four leaf clover using the mouth, and all four dicks cum at the same time.

Cindy was getting the ol' four leaf clover and ended up with a Shamrock Shake.

Shamrock Shake by Trent Gibbard January 7, 2020