WM and WMA layman, of Barn Park, Boscastle, Cornwall, the son of a WM grocer of Camelford. Listed in an 1847 Commercial Directory, with his Boscastle partner, as 'Wine and Spirit Merchants, General Merchants, Corn and Coal Merchants', he was also prominent as a slate quarry owner and boat owner, in which role he was also Lloyds agent. From 1828 he was an invalid, following an injury while unloading one of his ships at Boscastle.
He was circuit steward, local preacher and trustee in the Camelford WM Circuit. At Boscastle he rebuilt (or replaced) the chapel built by his father and had it 'pewed like a church'. In 1823 he introduced a pipe organ, without opposition. His wife, the niece of the rector of Phillack, Hayle, began the first Sunday School at Boscastle. Rosevear had a great interest in political reform and gave active support to the Whig candidate in the 1825 election; but he nonetheless named one of his ships 'The George Canning' after the moderate Tory. In church politics, while agreeing with Jabez Bunting on Catholic Emancipation, he opposed him on almost every other issue. Thus he became the local champion of Wesleyan Reform and was instrumental in leading some 90% of the members and local preachers of the Camelford Circuit into the WMA. It is unfortunate that no diary survives for this period. He died at Barn Park in 1853, having been for many years a member of the WMA Connexional Committee, described as 'a sincere and attached member and liberal supporter'.