Anti- (against)
Anti-
Against; opposite to.
Sana's new bicycle came with an anti-theft lock.
Antiseptic
Kills germs and stops infection.
Priya kept antiseptic liquid in the first-aid box.
Anticlockwise
In the opposite direction to a clock's hands.
Turn the lid anticlockwise to open the jar.
Remember: Anti- = against. Don't confuse it with ante- = before: a.m. stands for ante meridiem, 'before midday'.