UNSETTLE
faze, unnerve, enervate, unsettle
(verb) disturb the composure of
Source: WordNet® 3.1
Etymology
Verb
unsettle (third-person singular simple present unsettles, present participle unsettling, simple past and past participle unsettled)
To make upset or uncomfortable
To bring into disorder or disarray
Antonyms
• settle
Anagrams
• lunettes, tunelets
Source: Wiktionary
Un*set"tle, v. t. Etym: [1st pref. un- + settle.]
Definition: To move or loosen from a settled position or state; to unfix;
to displace; to disorder; to confuse.
Un*set"tle, v. i.
Definition: To become unsettled or unfixed; to be disordered. Shak.
Source: Webster’s Unabridged Dictionary 1913 Edition