What are synonyms for frustrate?

Here are some synonyms for "frustrate," categorized by nuance:

General Frustration:

* Disappoint

* Dissatisfy

* Vex

* Annoy

* Irritate

* Discourage

* Thwart

* Foil

* Hamper

* Hinder

* Obstruct

Frustration from Inability to Achieve:

* Deflate

* Dishearten

* Deaden

* Crush

* Stifle

* Block

* Impede

* Inhibit

* Paralyze

Frustration from Deliberate Interference:

* Sabotage

* Undermine

* Counteract

* Neutralize

Frustration from Being Useless:

* Render ineffective

* Nullify

* Make futile

Figurative/Poetic:

* Quash

* Stifle

* Derail

* Subvert

* Defy

The best synonym to use will depend on the specific context and the intended meaning.