Shamrock merujuk kepada seberapa jenis tumbuhan dalam keluarga [[Fabaceae]] yang dikenali kerana rupa [[Daun|dedaunnya]] yang tiga. Santo Patrick dipercayai menggunakan daun tumbuhan ini untuk menerangkan doktrin [[Tritunggal]] [[Gereja Katolik|Katolik]] –yakni, kepercayaan terhadap kewujudan Tuhan dalam bentuk "[[Tuhan Bapa|bapa]]", "[[Tuhan Anak|anak]]" dan "[[Roh Kudus|roh kudus]]" – kepada warga Ireland, lagi-lagi dengan adanya wujud [[dewi tiga]] dan motif seni ''[[Triskelion|triskeletriskelion]]'' dalam anutan dan adat asal masyarakat tersebut.<ref name="Monaghan2009">{{cite book|title=The Encyclopedia of Celtic Mythology and Folklore|last=Monaghan|first=Patricia|date=1 January 2009|publisher=Infobase Publishing|isbn=978-1-438-11037-0|quote=There is no evidence that the clover or wood sorrel (both of which are called shamrocks) were sacred to the Celts in any way. However, the Celts had a philosophical and cosmological vision of triplicity, with many of their divinities appearing in three. Thus when St. Patrick, attempting to convert the Druids on Beltane, held up a shamrock and discoursed on the Christian Trinity, the three-in-one god, he was doing more than finding a homely symbol for a complex religious concept. He was indicating knowledge of the significance of three in the Celtic realm, a knowledge that probably made his mission far easier and more successful than if he had been unaware of that number's meaning.}}</ref><ref name="Hegarty2012">{{cite book|title=Story of Ireland|last=Hegarty|first=Neil|date=24 April 2012|publisher=Ebury Publishing|isbn=978-1-448-14039-8|quote=In some ways, though, the Christian mission resonated: pre-Christian devotion was characterized by, for example, the worship of gods in groups of three, by sayings collected in threes (triads), and so on – from all of which the concept of the Holy Trinity was not so very far removed. Against this backdrop the myth of Patrick and his three-leafed shamrock fits quite neatly.}}</ref><ref>{{cite book|title=The Art of the Sublime: Principles of Christian Art and Architecture|last=Homan|first=Roger|publisher=Ashgate Publishing|year=2006|page=37}}</ref> Oleh itu pemakaian dan peragaan lambang dan reka bentuk syamrok sentiasa ada di mana sahaja perayaan ini disambut.<ref>{{cite web|url=http://news.nationalgeographic.com/news/2004/03/0312_040312_stpatrick_2.html|title=St. Patrick's Day: Fact vs. Fiction|accessdate=2009-03-31}}</ref><ref>{{cite web|url=http://www.csulb.edu/~d49er/spring00/news/v7n91-holiday.html|title=Holiday has history|accessdate=2009-03-21}}</ref> Ada juga sejarawan yang percaya bahawa dedaun ini turut dipilih kerana ia melambangkan "kelahiran semula" yang boleh diumpamakan dengan pemelukan agama Kristian diserukan Patrick.<ref name="Santino1995">{{cite book|url=https://archive.org/details/allaroundyear00jack/page/80|title=All Around the Year: Holidays and Celebrations in American Life|last=Santino|first=Jack|publisher=University of Illinois Press|year=1995|isbn=978-0-252-06516-3|page=[https://archive.org/details/allaroundyear00jack/page/80 80]}}</ref>
