facebook

Short definition from Wiktionary

Noun

1. 1
   A reference book or electronic directory containing the photographs and names of various individuals.
2. 2
   A college publication distributed at the start of the academic year by university administrations with the intention of helping students become acquainted with each other.
3. 3
   A personal web profile on the social-networking site Facebook.

Verb

1. 1
   Alternative letter-case form of Facebook.
2. 2
   To use the social-networking site Facebook.
3. 3
   To send a message or leave a comment on Facebook.

Proper noun

1. 1
   A social-networking website where users can find acquaintances or friends, exchange messages, and post updates.