spier / spire [ˈspaiɜr]
spier (spyer) – n. – one who watches or keeps someone or something under close observation, usually without their knowledge
spire – n. & v. – n. – 1. a tall, slender plant stalk such as a reed; 2. a pole of timber, a shaft, a pole; 3. one of the sinuous folds or windings of a snake, a coil; v. – 1. send forth or develop shoots, esp. the first shoot, germinate; 2. rise or extend to a height; 3. breathe slowly; 4. curl, twist, wind