All 5 Uses of

however
in
The Chocolate War

Worse than that, however, he had allowed Brother Leon to blackmail him.†
Chpt 16

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.

Today was zero hour, however.†
Chpt 22 *

however = a word used to connect contrasting ideas as when using "though", "in spite of that", "in contrast", "nevertheless", etc.

However, he managed to squeak by—no F's, only a couple of D's, all of which satisfied his father whom Emile regarded as stupid and whose major dream was to have his son graduate from a fancy private school like Trinity.†
Chpt 7

However, he'd seen some of the more prominent Vigil members waylaying kids in the corridors, checking on their sales, whispering menacingly to those who had sold only a few boxes.†
Chpt 29

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

(Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrastand but.)
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"