How do you approach reading really difficult books?

Ones that are totally filled to the brim with allusions and references that you don't know, words and phrases that you don't understand, i sometimes get stuck more in my dictionary or phone looking up the meanings after every line that i read, kills the flow of reading can't actually follow the story well cause i have to google something so frequently, worst is when you know all the words in the sentence but you don't get what it means and what the author's trying to say, like a different language made from all the recognisable English words. All these are just some (not all) examples of what i mean by "difficult".

I have been really wanting to start Pale Fire cause it sounds really interesting but I hesitate cause I'm wondering if I'll be able to even comprehend it or not cause i want to actually be able to enjoy the book instead of labouring on looking up the meanings in a dictionary every few seconds. Same for Pynchon titles, how do you tackle such books? I'm currently reading Borges and my only approach right now is giving a story multiple reads, reading slowly with a lot of deliberate focus and an internet connection to look up the obscure books and writers he mentions in his stories