When you get to the shop, if you click on the homonculus and look at your own perks, there is a glossary section that explains every notable word/build in more depth. A bit out of the way and not explained well, but it does explain each section
*btw: egg is a replacement of the "Free Cum" mechanic so Thrusts only, some perks will give eggs and you can have a maximum of 3 and when you thrust you deposit all egg stacks to add the egg stack buff to the lay. Said buff is kind of like the moon stacks for the werewolf in that they don't do anything without other perks, but perks can trigger off of eggs like "%chance to regain stamina for every egg stack".