The phrase "fresh lime" refers to a lime fruit that has not been processed, squeezed, or preserved. It means the lime is natural and has not gone through any changes or alterations.
To make the cilantro and onion topping... I mixed up 2 tablespoons of onion, 1 tablespoon cilantro, and a tablespoon of fresh lime juice. (jessicamurnane.com)
Whisk together 1/2 cup of fresh lime juice, 1 cup of sugar and 2 1/2 cups of water until the sugar is completely combined. (jerryjamesstone.com)
Stir in 1/4 cup hot sauce and 1 tablespoon fresh lime juice. (latortillafactory.com)