On marriage he conformed to the Established Church, studying at St David's College, Lampeter, where he became lecturer in Welsh.
Ordained deacon in 1848 and priest the following year he served curacies at Llandegwning parish in Llŷn and from 1852 to 1862 at nearby Llangian, Caernarfonshire.
According to Thomas Parry (History of Welsh Literature to 1900), Silvan Evans coined the word "telyneg" to render the English "lyric", hence the title of an early work, Telynegion (1846), which apparently contained translations from Anacreon, Sappho, Ovid, French sonnets, and the work of English poets, especially Lord Byron.
Parry judges Silvan Evans to have been overmuch influenced by William Owen Pughe's Dictionary in his use of vocabulary.
However, R. E. Hughes in the Dictionary of Welsh Biography (1959) claims that Evans "gradually became emancipated" from Pughe's work.