1. in the fourth place; as the fourth point in a sequence or list
Usage: used to introduce the fourth item in a series of points or arguments

Examples

• First, we need funding. Second, we need staff. Third, we need equipment. Fourthly, we need a clear timeline.
• Fourthly, it is important to consider the environmental impact of this decision.
• The proposal has several advantages: firstly, it is cost-effective; secondly, it is sustainable; thirdly, it improves efficiency; and fourthly, it enhances safety.
• Fourthly, the research shows that this method produces reliable results.
• She listed her reasons: firstly for health, secondly for convenience, thirdly for cost, and fourthly for environmental concerns.