Detailed Instructions: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
See one example below:
Problem: How are i.e. and e.g. pronounced?
Solution: i.e. stands for id est (Latin), which means 'that is'. You use it to link in a deeper explanation about something. Pronounce it 'eye - ee'. e.g. stands for exempli gratia (also Latin), which means 'for example'. You use it to link in an example of a more generic term. Pronounce it 'ee - jee'
Explanation: Perfect answer because it's consistent with context uses required information from the question to provide the detailed answer with an example.

Problem: I'm describing what an opiate addict looks like before recovery. Instead of saying 'he looked like a vampire,' I'd like to say something like 'he looked [vampiric].' I actually just found out vampiric was a word, but I want something that sounds better (more colloquial/natural, I suppose) and covers a variety of traits (pale, emaciated, sickly, etc). Why I don't just use 'vampiric': As @chepner commented: I think the idea is to find a word that isn't so 'circular', and doesn't refer explicitly to vampires or require knowledge of vampires in context. If someone were to ask 'What does a vampire look like?', then 'It looks vampiric/vampirish' wouldn't be terribly helpful. I don't want to explicitly refer to drug addicts as vampires. I just want to capture those traits in the best way.
Solution:
I'd suggest cadaverous. It incorporates many facets of what I believe you're trying to convey: a corpse-like appearance, including pallid and underweight. From Merriam-Webster.com: 1a : of or relating to a corpse b : suggestive of corpses or tombs 2a : PALLID, LIVID b : GAUNT, EMACIATED grossly underweight