Aciform is an adjective used to describe objects or shapes that resemble needles or cones. Some common synonyms for aciform include: needle-like, conical, coniform, pointed, sharp, and spiky. These words can be used to describe a wide range of objects, such as leaves, crystals, and ice formations. Aciform shapes can be found in nature, like pine trees and cactus needles, or created by humans, like the spiky roof of a castle turret. These synonyms can be used interchangeably to add interesting and descriptive language to your writing, whether you're describing nature, science, or architecture.