Back-formation from insipid. A direct borrowing from Latin would have instead yielded sapid, but neither of these words is much used in English; a most common synonym from this root is savoury.
sipid (comparative more sipid, superlative most sipid)
Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for “sipid”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.)