Sentence:  “And do you realize that in a few shakes I've got to show up at dinner and have Mrs Cream being very, very kind to me? It hurts the pride of the Woosters, Jeeves.” “My advice, sir, would be to <WSD>fortify</WSD> yourself for the ordeal.” “How?” “There are always cocktails, sir. Should I pour you another?” “You should.” 
Meaning of the word marked with <WSD> tags:  To impart strength or vigor to.