protective sheath
- casingEnclosing cover or frame
- sleeveGarment's arm portion
- coveringLayer that shields or hides
- armorProtective combat covering
- huskDry seed covering
shell · scabbard · myelin · insulation · skin · bark · rind · cocoon · membrane · wrapper · coating · guard · capsule · pod · holster · jacket · envelope · shroud
protection vs. exposure
protective sheathvulnerable point
Exposed weakness in defense
open wound · unshielded · unguarded · defenseless · weak spot