Sentence:  That same evening at tea-time — (I am sorry to have to introduce you to another eating-scene, but the hours in English households are usually marked by repasts. It is a daily calendar of feasts — breakfast <WSD>o'clock</WSD>, dinner <WSD>o'clock</WSD>, &c.,...). 
Meaning of the word marked with <WSD> tags:  In conjunction with a term representing an action or event that occurs daily, indicates the time that said action or event occurs, or first occurs.