勝手

Word: 勝手
Reading: かって
Level: N2
Part of speech: na-adjective
Meaning: arbitrary, one's own convenience
Example: 勝手な行動をとるのはやめてください。 Please stop acting on your own accord.
Confused with: 必ず (かならず): 必ず means without fail, whereas 勝手 means arbitrary.