invitation-n; 2 Senses

Sense Number 1: attendance request

Commentary: a request (spoken or written) to participate or be present or take part in something

Examples:
She threw the invitation away.
An invitation to lunch was sent to all the employees.

Mappings:
WordNet 2.0 Sense Numbers: 1

Sense Number 2: metaphoric

Commentary: a tempting allurement

Examples:
She was an invitation to trouble.

Mappings:
WordNet 2.0 Sense Numbers: 2