宿主

1. Origins, structure, and basic meaning

• Structure: 宿主 (しゅくしゅ) is a host on which a parasite or pathogen depends. It appears in a relationship and as an assigned role.
• Basic usage: A class diagrams parasite-host relations; an organism grows using a plant as host.

2. Common pitfalls and similar expressions

• Participant in a parasitic relationship and plant serving as host
  • 宿主の関係 links organisms; 宿主として assigns the plant's role. It does not mean a household host receiving guests.