Definition

1. Noun:
   • Tough-skinned larva of certain crane flies: A "leatherjacket" is the larval stage of a crane fly (often called a "daddy longlegs"). It is a legless, tough-skinned grub that lives in soil and can damage plant roots, especially grass.
   • Any of several New World tropical fishes having tiny embedded scales: In ichthyology, "leatherjacket" refers to various tropical marine fish, typically from the family Carangidae, known for their firm, leathery skin where the scales are small and embedded.
   • Any of several brightly colored tropical filefishes: "Leatherjacket" can also refer to certain species of filefish (family Monacanthidae), which are often brightly colored and have rough, sandpaper-like skin.

Usage Examples

• Noun (Crane Fly Larva):
  • The lawn has brown patches because of a leatherjacket infestation.
  • Birds often dig in the soil to find and eat leatherjackets.
• Noun (Tropical Fish):
  • We caught a small leatherjacket while fishing over the reef.
  • The leatherjacket's tough skin makes it difficult to clean for cooking.

Advanced Usage

• The term is primarily used in specific contexts: agriculture/pest control for the insect larva, and marine biology/fishing for the fish. It is not a common word in general conversation.
• When used without context, it most likely refers to the crane fly larva in regions like Europe and North America where they are a common lawn pest.

Variants and Related Words

• Leatherjack (noun): An alternative, less common spelling for the fish.
• Crane fly (noun): The adult flying insect whose larva is the leatherjacket.
• Daddy longlegs (noun): A common name for the crane fly in some regions (not to be confused with the harvestman arachnid also called daddy longlegs).

Synonyms

• For the larva: crane fly grub, soil grub.
• For the fish: (context-dependent) runner, skipjack (for some carangid species); filefish, triggerfish (related families).

Notes on Different Meanings

• The meanings are entirely distinct and belong to different fields (entomology vs. ichthyology). They share the name due to the perceived tough, leathery texture of the subject's skin or outer covering.
• There is no verb form or idiomatic usage for "leatherjacket."

Noun

1. tough-skinned larva of certain crane flies
2. any of several New World tropical fishes having tiny embedded scales
3. any of several brightly colored tropical filefishes