dramaturgy >n. the theory and practise of dramatic composition: studies of Shakespeare’s dramaturgy.

hippus >n. spasmodic or rhythmic contraction of the pupil of the eye, a symptom of some neurological conditions. 

sniffer >n. a person who sniffs, esp. one who sniffs a drug or toxic substance: a glue sniffer.

(informal) a device for detecting an invisible and dangerous substance, such as gas or radiation: electronic sniffers are used to detect the presence of a nuclear mass.

2. (informal) a person’s nose.

3. a computer program that detects and records a variety of restricted information, esp. the secret passwords needed to gain access to files or networks. 

tufa >n. a porous rock composed of calcium carbonate and formed by precipitation from water, e.g. around mineral springs.