sippyA little sip; less than a serving of some particular drink
SIPRNETThe Secret Internet Protocol Router Network: the U.S. Department of Defense's largest network for the exchange of classified information and messages at the SECRET level.
SipsonA village in the borough of Hillingdon, Greater London, England, just north of Heathrow Airport (OS grid ref TQ0777).
sipuleucelA vaccine therapy used to treat some cancers
sipunculanAny of many unsegmented marine worm-like animals, of the phylum Sipuncula, the peanut worms
sireA lord, master, or other person in authority, most commonly used vocatively: formerly in speaking to elders and superiors, later only when addressing a sovereign.
siredonA larval or neotenic salamander (e.g. the axolotl, Ambystoma mexicanum).
sirenOne of a group of nymphs who lured mariners to their death on the rocks.
SirenaicA member of the celebrated Fraternity of Sireniacal Gentlemen, a club that met at the Mermaid Tavern in Elizabethan London.
sireneA slightly crumbly brined cheese made of cow, sheep, or goatmilk, similar to feta; popular in the Balkan Peninsula.
SirengateThe AFL siren controversy surrounding the result of an Australian rules football match of 2006, when a point was scored after the end of the game because the umpire did not hear the siren.
sirenianA marine mammal of the order Sirenia, including the manatee and dugong, characterized by large forelimbs with no hind limbs.
sirenicResembling or relating to a mythical siren.
sirenicalLike, or appropriate to, a siren, i.e. deceptive;fascinating.
SiriuA commune and river in Buzău County, Romania.
SiriusA telescopic binary star, visually the brightest star in the night sky, a part of the northern constellation of Canis Major (the Greater Dog), one of three stars in the Winter Triangle asterism. Long understood as a single extremely luminous white star, it was associated in ancient Egypt with the Nile flood and in Greek and Roman culture with the "dog days" of summer.
SirkeciA neighbourhood of Eminönü, Fatih district, Istanbul, Turkey.
sirkeerAny of several species of Asiatic cuckoos of the genus Taccocua.
SirkianOf or relating to Douglas Sirk (1897–1987), German film director best known for his work in Hollywood melodramas of the 1950s.
sirkyA kind of unplaited matting formed by laying the fine cylindrical culms from the upper part of the grass Tripidium bengalense side by side, and binding them in single or double layers. It may be laid under the thatch of a house, used to cover carts and palanquins, to make table-mats, etc.
sirolimusAn immunosuppressive drug C₅₁H₇₉NO₁₃ that is a macrocyclic lactone obtained from a soil bacterium Streptomyces hygroscopicus and is taken orally especially to prevent rejection of transplanted organs.
SironaA Celtic goddess of healing associated with healing springs.
sirrahA term of address to an inferior male or more commonly a child. A modern-day equivalent would be "little man".
sirrushA fantastical creature depicted on the reconstructed Ishtar Gate of Babylon, a scaly dragon with hind legs like an eagle's talons and feline forelegs.