Sentence:  The precise size and shape of a <WSD>shillelagh</WSD> can be hard to agree upon, but most of those who have an interest in Irish culture will readily acknowledge that a knobbed stick, made of oak or blackthorn, are the distinguishing characteristics of a <WSD>shillelagh</WSD>. 
Meaning of the word marked with <WSD> tags:  A wooden (traditionally blackthorn (sloe) wood) club ending with a large knob.