vex
verb
[VN] (old-fashioned or formal) to annoy or worry sb:
The memory of their conversation still vexed him.
vexing adjective:
a vexing problem / question I found their attitude extremely vexing.

• Từ trái nghĩa / Antonyms: reassure   assure  
• Từ đồng nghĩa / Synonyms: perplex   stick   get   puzzle   mystify   baffle   beat   pose   bewilder   agitate   disturb   commove   shake up   stir up   raise up   worry