Saṃgha (lit.: congregation), is the name for the Community of Buddhist monks. As the third of the Three Gems or Jewels (ti-ratana, q.v.) and the Three Refuges (ti-saraṇa, q.v.), i.e. Buddha, Dhamma and Saṃgha, it applies to the ariya-saṃgha, the community of the saints, i.e. the 4 Noble Ones (ariya-pugga, q.v.), the Stream-winner, etc.

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA

saṃ-gha m. (fr. sam + √han) 'close contact or combination', any collection or assemblage, heap, multitude, quantity, crowd, host, number (generally with gen. pl. or ifc., e.g. muni-s○, 'a multitude of sages' BhP
• śatru-s○, a host of enemies Rājat.) MBh. Kāv. &c
• any number of people living together for a certain purpose, a society, association, company, community
• a clerical community, congregation, church Mn. Sāh. &c
• (esp.) the whole community or collective body or brotherhood of monks (with Buddhists
• also applied to a monkish fraternity or sect among Jainas) Buddh. Sarvad. MWB. 176

Sanskrit-English Dictionary, by M. Monier William