1. A waxy, petroleum-based protective coating or lubricant used to prevent rust and corrosion on metal surfaces, especially firearms and machinery.
Usage: Often used in military and industrial contexts; Cosmoline is a trademark, but the term is used generically

1. To coat or treat (a metal object) with cosmoline to protect it from rust and corrosion.
Usage: Third-person singular present or plural form

Examples

• The rifle was covered in cosmolines to protect it during storage.
• Military equipment is often cosmolined before being shipped overseas.
• He carefully removed the cosmolines from the vintage firearm.
• The factory cosmolines all metal parts before packaging.
• Cosmolines can be difficult to clean off without proper solvents.