syn- Also syl-, sym-, and sys-.
United; acting or considered together; alike.
[Greek sun, with, together.]
A synapse (Greek hapsis, joining) is a junction between two nerve cells; a syndrome (Greek dramein, to run) is a group of symptoms which consistently occur together; synthesis (Greek thesis, placing) has various senses meaning combination or composition; a synonym (Greek onoma, name) is a word or phrase that has nearly the same meaning as another; syntax (Greek tassein, arrange), is the arrangement of words and phrases to create well-formed sentences in a language; a synagogue is literally a place where people come together, from Greek agein, to bring; synod, an assembly of the clergy and sometimes also the laity, derives from Greek hodos, way
In many words brought into English through Latin, the prefix changes its final letter before certain consonants. Before l, it becomes syl-: syllable (Greek lambanein, take); before b, m, or p, it becomes sym-: symbiosis (Greek bios, livelihood), symmetry (Greek metron, measure), sympathy (Greek pathos, feeling). Before s, it becomes sys-, though examples are rare: syssarcosis, the joining or attachment of bones by means of muscle (Greek sarx, flesh).