確実

Word: 確実
Reading: かくじつ
Level: N3
Part of speech: na-adjective
Meaning: certainty, reliability
Example: 明日の会議には確実に出席します。I will certainly attend the meeting tomorrow.
Confused with: 確か (tashika) - Tashiaka is more about 'if I recall correctly', while kakujitsu is about certainty.