tic / tick [tɪk]
tic – n. – spontaneous, spasmodic twitching of certain muscles
tick – n. & v. – n. – 1. the common name for several species related, to but larger than, mites or acarids; 2. a thin mattress often containing feathers; 3. a light, but distinct, quick stroke or tap; 4. rhythmic tapping such as a clock; v. – 1. whip up or lift quickly; 2. pat gently; 3. give credit; 4. make a muted oscillating sound