on the safe side
Avoiding potential dangers, problems, or challenges; choosing a course of action less fraught with risk. I made an extra batch of brownies, just to be on the safe side in case we have more guests than we anticipated. We'd probably be fine with three cases, but I'd rather we have at least four to stay on the safe side.
on the safe side
Fig. taking the risk-free path. Let's be on the safe side and call first. I think you should stay on the safe side and call the doctor about this fever.
on the safe side
Avoiding danger, with a margin for error, as in Just to be on the safe side, let's order another hundred chairs. This idiom was first recorded in 1811.
on the safe side
mod. taking the risk-free path. Let’s be on the safe side and call first.