Valetudinarian (noun or adjective): weak or sickly person, especially one morbidly concerned with his or her health.
Picayune
Also, Askance, I believe you want the word **Aglet **for your shoelace end, not Anglet.
Virago - Female warrior, heroine. Caution, however, because apparently among the few people who know the term it has come to mean something like ‘harpy’.
Hobbledehoy - a youth, particularly an ungainly one
Here are some mentioned in Mrs. Byrne’s Dictionary of Unusual, Obscure and Preposterous Words that I can’t find in Dictionary.com:
Dwergmal - an echo; literally, dwarf-language, the echoing rocks being the supposed home of the dwarfs (Norse Saga).
Thrion - the figleaf garb of Adam and Eve
Cleocentric - adj. pertaining to the belief that fame is everything
Spintry - A male whore
I just learned the word Panjandrum today.
My favorite is probably egregious (conspicuously bad).
I came in to post that one. Are you a Spider Robinson fan? I think it was one of his stories I got that from.
Yes, and one of my favorite fonts is aptly-named Bifur . . . ***divided ***between black areas and striped (or sometimes colored) areas.
When I learned the word from a word vocabulary book in about 1970 (Increase Your Word Power Now! or something like that), it was as a synonym for fishwife and termagant. (I laughed when a car was named Virago.) The warrior definition is considered to be archaic even in my 1975 dictionary. Maybe you’re a LOT older than I expected!
I am(and I do think I’ve seen it referenced in one of his books somewhere), but I originally got it from my dad, who’s a geologist. 
Wikipedia has something to say on this. I don’t remember where I first encountered the term in English (though in Latin I’m pretty sure I saw it used to describe Camilla) but I only found out about its negative connotations when I looked it up recently. But it’s a nice, visceral word that deserves to be reclaimed.
supercalifragilisticexpialidocious (Somebody had to mention this one). It’s the title of a song in Mary Poppins. Means great, fantastic. (11’300 hits in Google). And in the 60s there was a huge advertising panel in New York for Kellog’s cornflakes.
(not really part of my vocabulary though) 
Straight Dope column on supercalifragilisticexpialidocious:
I was surprised to learn that the word predated Mary Poppins.
The Wikipedia article is less help, citing Cecil himself:
Not all that esoteric, thanks to Poe:
Tintinnabulation: a ringing or tinkling sound.
Cecil and Wikipedia are wrong. The word was invented by Staff Report guest poster NYNJVATXPA.
If Dakka isn’t generally recognized yet, it ought to be. As the Tropes page defines it: “<…>slang for rapid fire capability, based on the onomatopoeia for automatic guns shooting. <…>”. And by extension, the concept of overwhelming, obliterating firepower.
coup de grace but I hear too many people pronounce it as if it meant “blow or strike of fat” vs. “strike of thanks/mercy”. The French word, gras, meaning fat, is pronounced grah. The French word, grace, is pronounced grahss. (Sorry, I can’t find my list of accent codes.)
calipygian - adj. - nice-assed.
I’m a typical male pig.
Dang. That was my word. I work with UID (Unique Identification) codes for government systems. It’s a 2D barcode that stores a whole lot of information. We have to have our manufacturer’s code, the part number, and the serial number in this code. The whole string of numbers is concatenated before it’s decoded by the reading software. I use it in meetings whenever possible.
My other one is pandiculation: a stretching and stiffening especially of the trunk and extremities (as when fatigued and drowsy or after waking from sleep).
Pharology (the study of lighthouses and beacons)
Vexilology (the study of flags and banners)
and (this one is not a word, but should be)Ferroequinology (the study of locomotives)
Even better if you use Greek roots throughout and render it siderohippology. 
Many of the words listed, thus far, are not really esoteric.
It doesn’t mean unusual words that few people are aware of.
My favorite esoteric phrase is homonymous hemianopsia, which is also called a visual field cut.