Word games - sexual attraction again

I'm gonna do a really quick side post here because I'm in the middle of writing a longer post on "what is sex, anyway", and it doesn't look like it's gonna be finished any time soon. So this post is just to express some of my frustration and to demonstrate the circular nature of the concepts we use and the seeming impossibility to break into that self-contained universe unless you already know what it's talking about.

One concept that I would really like defined, is the ever elusive sexual attraction. I mean, what literally, concretely, specifically happens in the experience of people, in their bodies, in their emotions, in their perceptions, that they then go and label that "sexual attraction". It's an open question to anyone who wants to answer it.

Here are the results of my wild goose chase around dictionaries:
sexual attraction: attractiveness on the basis of sexual desire
sexual desire: a desire for sexual intimacy
sexual intimacy: (no definition)
sexual: of or relating to or characterized by sexuality
sexuality: sex
sex: sexual activity
sexual activity: activities associated with sexual intercourse
sexual intercourse: the act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur

Well there we go. Apparently sexual attraction is all about desiring to insert penises into vaginas and exciting them until ejaculation occurs.

I have a sense that even some sexuals would find that definition too narrow and limiting.

Does anyone else get a feeling that there is a LOT of vagueness and indirectness here? Like every time you ask, you get sent to someone else (or some other dictionary entry) that might answer your question. These terms are either not well and clearly defined and explained, or I don't inhabit the same experiential universe as the dictionary-makers.

Imagine that you come from Alfa Centauri and you know nothing about "wug" (stand-in for "sex" here). Now go and read articles attempting to define "sexual attraction/desire" and replace "sex" with the word "wug" and see how self-referential they are and how they don't really explain anything in a helpful way. It's all about the externals of the experience - what influences it, what different kinds there are, what disciplines have studied it, what it has been called and how it has been classified, where and in which species it exists, what are some other words to call it, what can adversely affect it - but really NOTHING about IT, from the inside, how IT feels! As if we all know what we are talking about.