15-letter words containing b, i, o, s, y
- sepoy rebellion — the Indian Mutiny of 1857–58
- sibylline books — (in ancient Rome) a collection of prophetic sayings, supposedly bought from the Cumaean sibyl, bearing upon Roman policy and religion
- social mobility — mobility (def 2).
- sons of liberty — any of several patriotic societies, originally secret, that opposed the Stamp Act and thereafter supported moves for American independence.
- sound symbolism — a nonarbitrary connection between phonetic features of linguistic items and their meanings, as in the frequent occurrence of close vowels in words denoting smallness, as petite and teeny-weeny.
- spanish bayonet — any of certain plants belonging to the genus Yucca, of the agave family, having narrow, spine-tipped leaves and a cluster of white flowers.
- spiny cocklebur — a cocklebur, Xanthium spinosum, introduced into North America from Europe.
- strephosymbolia — a condition of perceiving objects as their mirror image and, specifically, having difficulty in distinguishing letters in words
- subperiosteally — the normal investment of bone, consisting of a dense, fibrous outer layer, to which muscles attach, and a more delicate, inner layer capable of forming bone.
- subreptitiously — in a subreptitious manner
- subsidiary coin — a coin, especially one made of silver, having a value less than that of the monetary unit.
- substitutionary — a person or thing acting or serving in place of another.
- swing both ways — to enjoy sexual partners of both sexes
- syllabification — to form or divide into syllables.
- symbol retailer — any member of a voluntary group of independent retailers, often using a common name or symbol, formed to obtain better prices from wholesalers or manufacturers in competition with supermarket chains
- symbolics, inc. — (company) The company which produced the Lisp Machine.
- synod of whitby — the synod held in 664 at Whitby at which the Roman date for Easter was accepted and the Church in England became aligned with Rome
- urban sociology — the sociological study of cities and their role in the development of society.